Destroyer Problems

Question 1

A colorblind man marries a normal woman. If they have children, what is the probability that their son will be colorblind?

Answer 1

• 0 %
• 100 % of the girls are carriers
• color blindness and hemophilia are classic examples of sex-linked diseases.

Question 2

If a single ancestral species was to evolve into a variety of forms, this would be an example of:

Answer 2

• adaptive radiation
• in adaptive radiation, we see a number of different species emerge from a single ancestor. This exemplifies a divergent evolution. The finches on the Galapagos islands are an example.

Question 3

Down Syndrome

Answer 3

• Trisomy 21, 47 chromosomes

Question 4

Turner Syndrome

Answer 4

• 45 chromosomes

- lacking an x chromosome

Question 5

Klinefelter Syndrome

Answer 5

• XXY or XXXY

Question 6

Which pair is incorrectly matched?

a. Klinefelter Sydrome: 44 autosomes + XXY
b. Turner Syndrome: sterile female lacking X
c. Down Syndrome: 47 chromosomes
d. Hemophilia: sex-disorder
e. All are correct

Answer 6

e. All are correct

Question 7

Which pair is correctly matched?

a. spermatogenesis: vas deferens
b. sperm maturation: seminiferous tubules
c. sperm expulsion: vas deferens
d. spermatogenesis: prostate
e. two of the above

Answer 7

c. sperm expulsion: vas deferens

Question 8

Which statement is false?

a. acquried characteristics are not transmitted to the progeny
b. in Canis lupus, Canis is the genus; lupus is the species
c. Darwin suggested that variation in traits are due to mutations
d. Finches on the Galapagos Islands originated from a single species, adaptive radiation
e. early earth had a reducing atmosphere of NH3, H2S, and CH4

Answer 8

c. Darwin suggested that variation in traits are due to mutations
- Darwin didn’t have an understanding of genetics

Question 9

The initiation of the heart beat is largely controlled by:

a. bundle of His
b. AV node
c. SA node
d. Epinephrine
e. blood CO2 levels

Answer 9

c. SA node
- called the pacemaker, SA node is located at the entrance of right atrium. This node delivers electrical impulses at regular intervals that allow the heart to beat. This electrical excitation causes the atria to contract, thus pushing blood into the ventricles.

Question 10

Which statement is false?

a. Invertebrates include Mollusks, Arthropods, Annelids and Echinoderms
b. An Amphioxus is a vertebrate
c. Monkeys, apes and man are all primates
d. A viviparous mammal is one in which the offspring develop within the uterus
e. The duck-billed platypus is an egg-laying mammal

Answer 10

b. An Amphioxus is a vertebrate
- Amphioxus is an invertebrate. Amphioxus and tunicates are chordates that are not vertebrates. Chordates have a notochord at least some time during development. The amphioxus and tunicates do not lose their notochord.

Question 11

Which hormone stimulates the release of bile?

a. Enterogastrone
b. Cholecystokinin
c. Bilease
d. Secretin
e. Gastrin

Answer 11

b. Cholecystokinin

• Cholecystokinin is a hormone made by cells of the duodenum (first part of small intestine) that stimulates bile release.
• secreting -> pancreatic juice, especially bicarbonate
• Gastrin made in the stomach -> HCl secretion

Question 12

Which is false about osteoporosis?

a. bones become fragile and more likely to fracture
b. bone density increases
c. estrogen can help maintain bone density
d. prevention includes Ca and Vitamin D
e. All are true

Answer 12

b. bone density increases

Question 13

Which of the following is a glucocorticoid?

a. Aldesterone
b. Serotonin
c. Trypsin
d. Cortisol
e. Epinephrine

Answer 13

d. Cortisol
- cortisol is a glucocorticoid isolated from the adrenal cortex and promotes synthesis of glucose from sources such as proteins.

Question 14

Which statement(s) is false?

a. chemoreceptors located on the aorta and carotid arteries are involved in blood gas content monitoring
b. a small increase in {H+|} would dec breathing rate
c. low blood CO2 would dec breathing rate
d. high blood O2 would dec breathing rate.
e. two of the above

Answer 14

b. a small increase in {H+|} would dec breathing rate
- The chemoreceptors are specialized structures in the walls of major arteries. They detect changes in H+, O2 and CO2. breathing rate is very sensitive to blood CO2 and H+ conc. A small incre in either H+ or CO2 will cause an incr in breathing rate. a high blood O2 pressure would dec breathing rate.

Question 15

A stable complex of CO and hemoglobin in RBCs is termed:

a. Carboxyhemoglobin
b. Carbaminohemoglobin
c. Oxyhemoglobin
d. Deoxyhemoglobin
e. 2,3 - BPG

Answer 15

a. Carboxyhemoglobin

- Carbaminohemoglobin is CO2 bound Hb

Question 16

Which statement is false?

a. the somatic nervous system contains both sensory and motor neurons
b. the autonomic nervous system contains only motor neurons
c. equilibrium and balance are controlled by the cerebellum
d. the corpus callosum is a large myelinated tract that connects the bases of the cerebral hemispheres
e. all of the above are true

Answer 16

b. the autonomic nervous system contains only motor neurons

• cerebellum is that part of the brain involved w/ muscle coordination, balance and equilibrium.
• corpus callosum divides the brain hemispheres. It is one of the largest myelinated tracts. It allows the right and left-brain portions to communicate.

Question 17

Which two plant hormones are involved in root growth and stem elongation?

a. auxins and ethylene
b. gibberellins and abscisic acid
c. auxins and gibberellins
d. ethylene and auxins
e. cytokines and abscisic acid

Answer 17

c. auxins and gibberellins

• ethylene promotes fruit repening
• abscisic acid inhibits growth
• cytokines involved in stimulating cell division

Question 18

Which is false about the liver?

a. albumin synthesis
b. bile production
c. dest or worn out RBCs
d. converts nitrogenous wast to urea
e. glucose storage

Answer 18

e. glucose storage.

• liver stores glycogen not glucose
• insulin from beta cells of pancreas decre blood glucose by converting it to glycogen where it is stored in liver and muscle cells

Question 19

which statement about the kidney is true?

a. most resorption occurs in proximal convo tubule
b. birds have long loop of henle thus conc urine
c. urine pass: distal conv -> collecting duct
d. vasopressin (ADH) absent -> walls of collecting duct impermeable to water
e. all are true

Answer 19

e. all are true

Question 20

where is urea made?

a. kidneys
b. liver
c. lungs
d. gall bladder
e. thyroid

Answer 20

b. liver

- urea is major product of nitrogen metabolism. it is formed in the liver and transported to kidneys for excretion

Question 21

which of the following lack a dorsal hollow nerve cord?

a. snake
b. alligator
c. human
d. frog
e. none. all contain dorsal hollow nerve cord

Answer 21

e. none. all contain dorsal hollow nerve cord.
- dorsal hollow nerve cord is one of the embryonic features of chordates. chordates also have a notochord, pharyngeal slits, and a muscular post-anal tail. The nerve cord of a chordate develops into the brain and spinal cord. Snakes, alligators, humans, amphibians are all chordates, thus all contain a dorsal hollow nerve cord.

Question 22

a restriction endonuclease recognizes a specific sequence and makes a cut within a DNA molecule. This specific sequence is called a(n):

a. exon
b. intron
c. palindrome
d. promoter
e. operator

Answer 22

c. palindrome

• each restriction endonuclease hydrolyzes only a specific bond in DNA. This sequence is known as a palindrome.
• a palindrome sequence can occur w/ DNA or RNA

Question 23

urine leaves the kidney via:

a. proximal convoluted tubule
b. urethra
c. renal artery
d. urinary bladder
e. none of these

Answer 23

e. none of these

- urine leaves kidney via way of ureters. Ureters -> urinary bladder (stored) -> urethra

Question 24

Which is true about the kangroo rat?

a. seeds eaten are high in protein, but low in fat
b. seeds eaten are high in protein and fat
c. seeds eaten are high in fat but low in protein
d. fecal matter is wtery in consistency
e. two of the above

Answer 24

c. seeds eaten are high in fat but low in protein
- kangroo rat can survive by eating dry seeds high in fat and carbohydrate but low in protein. oxidation of fat provides the needed water for survival.

Question 25

In an erythrocyte, where does the TCA cycle (krebs cycle) occur?

a. matrix of mitochondria
b. inner membrane of mitochondria
c. cell membrane
d. cytosol
e. none of these

Answer 25

e. none of these

- RBC don’t have mitochondria. RBC derive energy from glycolysis; anaerobic respiration occuring in cytosol.

Question 26

Which statement is false?

a. as degree of unsat of a cell membrane incr, fluid incr
b. as number of double bonds in a fatty acid incr, fluidity of membrane increases
c. if an E. Coli is put in warmer environment, compensation would be to incre unsat fatty acid content of its membrane
d. lindividual lipid molecules can diffuse freely in a lateral fashion within bilayer surface
e. prokaryotes lack cholesterol in their cell membrane, unlike eukaryotes

Answer 26

c. if an E. Coli is put in warmer environment, compensation would be to incre unsat fatty acid content of its membrane
- in warmer environment, organism would want to incre % of saturated acids to ensure membrane doesn’t get too fluid.

Question 27

which statement is false?

a. smooth muscle contractions that allow food to move through GI are called peristalsis
b. most enzymatic hydrolysis occurs in small intestine
c. first macromolecules to undergo enzymatic hydrolysis in digestive tract are carbohydrates
d. amino acids and sugars are carried away from intestine by bloodstream
e. nutrient-laden blood from villi is transported to renal system for clearance

Answer 27

e. nutrient-laden blood from villi is transported to renal system for clearance
- villus of small intestine contain a capillary network and lacteal that absorb nutrients. nutrients carried to bloodstream. nutrient rich blood goes through hepatic portal vein to liver which will regulate blood nutrient content. excess glucose removed from blood and stored in liver as glycogen. liver will remove excess glucose and amino acids from blood to prevent tissue damage. blood leaves liver and goes to heart which pump to rest of body.
- villi -> bloodstream -> liver -> heart -> body

Question 28

N2 IS replenished into the atmosphere by….?

a. nitrifying bacteria
b. methanogens
c. cyanobacteria
d. nitrogen-fixing bacteria
e. denitrifying bacteria

Answer 28

e. denitrifying bacteria
- denitrifying bacteria convert nitrates or nitrites to free N2. in order for this to occur, there must be insufficient O2 present causing use of NO3- or NO2- instead of O2
- Nitrogen-fixing bacteria convert N2 to nitrogen-containing species needed by plant.

Question 29

which of the following is incorrectly matched

a. fish: 2 chambered heart
b. frog: 3 chambered heart
c. artery: no valves
d. pulmonary vein: oxygenated blood
e. ascending loop of henle: permeable to H2O

Answer 29

e. ascending loop of henle: permeable to H2O
- cells of ascending loop are impermebale to H2O. as urine descends loop of henle, it becomes more and more concentrated and becomes less concentrated in the ascending branch. ascending branch is permeable to NaCl (active transport) -> hyperosmotic environment pulling H2O out of descending loop.

Question 30

which DNA sequence is a palindrome and could be a potential restriction enzyme site?

a. GAATCG
b. CCTAGG
c. AAAAA
d. GGGGG
e. GGCCGG

Answer 30

b. CCTAGG
- a palindrome sequence is read the same from left to right as from right to left. complementary sequence is: GGATCC

CCTAGG
GGATCC

Question 31

which statement is true?

a. muscle contraction: A band shortens, I and H zone don’t change
b. muscle contraction: A band doesn’t change length, but I band and H zone shorten
c. sarcomere is the basic unit of striated muscle tissue. it represents the structural unit of a myofibril
d. a and c
e. b and c

Answer 31

e. b and c

• distance between two z lines will define a sarcomere
• during muscle contraction, I band and H zone shorten while the A band stays the same.

Question 32

A somatic cell during late interphase has been observed to have 10 chromosomes. how many chromatids is this?

a. 5
b. 10
c. 20
d. 49
e. 15

Answer 32

c. 20

Question 33

Chlorophyll is similar in structure to:

a. thyroxin
b. epinephrine
c. hemoglobin
d. cholesterol
e. urea

Answer 33

c. hemoglobin
- chlorophyll is similar to the heme group in myoglobin, hemoglobin, and cytochromes. in chlorophyll, the metal is Mg rather than Fe.

Question 34

There are nearly 900 species of birds. Birds most likely are descendents of:

a. amphibians
b. Lobe-finned fish
c. reptiles
d. mammals
e. none of the above

Answer 34

c. reptiles

- birds may have descended from dinosaurs

Question 35

The rise in which ion triggers the cortical reaction and incites metabolic changes within an egg cell:

a. Mg++
b. Ca++
c. Ba++
d. Na++
e. Cli

Answer 35

b. Ca++

• a wave of Ca++ is released from the endoplasmic reticulum and functions as second messenger. a high conc of Ca++ is vital for the cortical reaction to occur.
• cortical reaction prevents polyspermy.

Question 36

Bacteria derive their energy from:

a. krebs cycle
b. glycolysis
c. electron transport chain
d. a and b
e. b and c

Answer 36

e. b and c
- prokaryotes don’t have mitochondria and do not carry out TCA cycle, but they do carry out glycolysis and have their own electron transport system

Question 37

which structure is considered the link between the nervous system and the endocrine system?

a. thalamus
b. hypothalamus
c. adrenal cortex
d. medulla
e. pineal gland

Answer 37

b. hypothalamus
- hypothalamus is the link between the endocrine and the nervous system. the hypothalamus will regulate the heart, arterial blood pressure, produce neurosecretoy substances, regulate H2O and electolyte balance, body temperature, and maintain homeostasis.

Question 38

The common bile duct carries bile from gall bladder and conduits it into the………..

a. ileum
b. jejunum
c. duodenum
d. pylorus
e. liver

Answer 38

c. duodenum

- bile is brought to first part of small intestine by the common bile duct

Question 39

2,4-DNP is an uncoupler. What effect does this compound have on the electron transport system?

a. e- flow stops, ATP synthesis cease
b. e- flow continue, ATP synthesis increase
c. e- flow continue, ATP synthesis cease
d. e- flow stop, ATP synthesis unchanged
e. no effect

Answer 39

c. e- flow continue, ATP synthesis cease

- uncoupling agents prevent the generation of H+ gradient

Question 40

Where is chlorophyll found?

a. intermembrane space
b. thylakoid membrane
c. cell wall
d. mitochondria
e. none of these

Answer 40

b. thylakoid membrane

-

Question 41

Which is incorrectly matched?

a. Rhizoids: root-like absorptive structures in some fungi and plants
b. seed; similar to fertilized egg
c. sepal: encloses and protects the flower bud in angiosperms
d. moss: seed-containing vascular plant
e. seed: includes the young, dormant sporophyte, nutritive tissue, and outer protective coat

Answer 41

d. moss: seed-containing vascular plant

- moss and ferns don’t have seeds

Question 42

Leydig cells and Islet of Langerhans will produce:

a. enzymes
b. hormones
c. neurotrnansmitters
d. prostaglandins
e. euocytes

Answer 42

b. hormones
- lslet of Langerhans cells are collection of cells in pancreas. alpha cells will produce glucagon and beta cells will produce insulin. Leydig cells are present at puberty and produce testosterone

Question 43

Which statement is false?

a. a net gain of 2 ATP is seen when glucose forms lactate
b. glycolysis is anaerobic respiration and can supply energy even if no TCA cycle operates
c. actively contracting muscle tissue has a higher amount of pyruvate than resting muscle tissue
d. in yeasts growing anaerobically, pyruvate is converted into ethanol
e. gluconeogenesis occurs to produce glucose from non-carbohydrate precursors

Answer 43

c. actively contracting muscle tissue has a higher amount of pyruvate than resting muscle tissue (false)
- in active muscle, there is a high amount of lactate. Lactate formation produces NAD+ which is necessary for glycolysis to continue.

Question 44

Cyanobacteria are likely to be found in:

a. petroleum deposits
b. freshwater and marine habitats
c. lava flow
d. high saline environments
e. area of no oxygen

Answer 44

b. freshwater and marine habitats
- cyanobacteria or “blue-green” algae are aquatic as well as photosynthetic. they are the oldest known fossils and generated the O2 in the early earth. Nutrient rich bodies of water such as ponds or lakes may support rapid growth of cyanobacteria and make the water green or blue-green within a short period of time.

Question 45

which statement is true?

a. the cycle that occurs in many animals to produce urea is called ornithine cycle
b. the removal of amine group from proteins is called deamination
c. NH3 is toxic to many cells and is converted to urea in humans
d. after deamination, amino acids composed of elements such as carbon, oxygen, and hydrogen can produce ATP, or even make glucose
e. all are true

Answer 45

e. all are true
- when amino acids are absorbed by liver cells, a series of chemical reactions take place. first, the amino group is removed; this is called deamination. the amino group is then reduced to NH3. NH3 is made into urea in the liver by the ornithine cycle. the urea can diffuse into the blood and be excreted as urine. the rest of the amino acid is recycled or oxidized for energy needs. amino acids can also produce glucose in a process called gluconeogenesis (liver)

Question 46

which statement is false?

a. metabolic acidosis is caused by an excess of H+ in blood
b. vomiting can cause metabolic acidosis
c. hyperventilation will result in a respiratory acidosis
d. b and c
e. none. all are true

Answer 46

d. b and c
- metabolic acidosis is due to excess H+ in blood. during metabolic alkalosis, the bicarbonate ion is greater than the carbonic acid concentration. vomiting causes loss of stomach acid, hence alkalosis, not acidosis will occur. In hyperventilation, you lose CO and you breathe rapidly which will cause respiratory alklalosis. Only choice “a” is correct.

Question 47

Which statement is true?

a. a sweat gland is an apocrine gland
b. sweat gland activity decreases with increasing age
c. as the body temperature rises, dermal blood vessels dilate
d. a sweat gland is an eccrine gland
e. all of the above

Answer 47

e. all of the above

• some sweat glands are apocrine -> responds to stress, some are eccrine -> maintain body temperature.
• as we age, the activity of sweat glands decrease, and may become replaced by fibrous tissue. also, as one ages, the skin becomes dry and loses oils: this is due to decrease in sebaceous gland activity.
• as the body temperature increases, blood vessels dilate, this allows blood to enter the dermis and can dissipate some of the heat.

Question 48

problem 260 if time permits

Answer 48

?

Question 49

which organism is known for causing serious disease in man:

a. chordates
b. reptiles
c. roundworms and flatworms
d. cnidarians
e. sponges

Answer 49

c. roundworms and flatworms

Question 50

what reaction occurs in matrix of mitochondria?

a. krebs cycle
b. acetyl coA accumulation
c. fatty acid oxidation
d. two of these only
e. A, B, and C

Answer 50

e. A, B, and C

- Acetyl coA accumulates in matrix since pyruvate decarboxylates to enter the krebs cycle as acetyl coA.

Question 51

Melanin is a pigment produced by specialized cells called melanocytes. In which layer would melanocytes most likely be found?

a. dermis
b. stratum corneum
c. stratum germinativum
d. two of the above
e. all of the above

Answer 51

c. stratum germinativum
- the deepest layer of the epidermis is called germinativum. this layer contains the melanocytes. the stratum corneum is the outermost layer containing the dead epithelial cells. the dermis is below the epidermis. the dermis consists of connective tissue, containing erector muscles, hair follicles, sensory receptors, sweat and sebaceious glands.

Question 52

serous membranes associated with the lungs are called?

a. pleurae
b. alveoli
c. sinuses
d. peritoneum
e. pinna

Answer 52

a. pleurae
- the lungs have a thin, smooth membranous outer covering called pleurae. Alveoli are the basic respiratory units where actual gas exchange occurs by passive diffusion. A sinus is a cavity or hollow space in bone. Peritoneum is the tissue that covers all the digestive organs and lines the body cavity. The fleshy, outer portion of the external ear is the pinna.

Question 53

Which statement is false?

a. arterioles offer the greatest resistance to blood flow in the circulation
b. mature red blood cells lack a nucleus
c. striated muscle such as cardiac and skeletal are composed of sarcomeres
d. cardiac output = stroke volume x heart rate
e. as stroke volume increases, cardiac output decreases

Answer 53

e. as stroke volume increases, cardiac output decreases
- stroke volume is the volume of blood discharged from the ventricles w/ each contraction. the volume that is discharged from the ventricle each minute is the cardiac output.

cardiac output = stroke volume x heart rate

Question 54

What regulates the passage of food from the stomach to the duodenum of the small intestine?

a. ileocecal valve
b. pyloric sphincter
c. epiglottis
d. esophageal sphincter
e. gall bladder

Answer 54

b. pyloric sphincter

- pyloric sphincter prevents food regurgitation from the intestine back into the stomach

Question 55

Hemophilia and color-blindness?

Answer 55

X-linked recessive

Question 56

Which of the following has a four chambered heart?

a. a robin
b. a trout
c. a shark
d. a reptile
e. an amphibian

Answer 56

a. a robin
- mammals and birds have four chambered hearts. Fish have two chambered hearts. Amphibians and reptiles have three chambered hearts.

Question 57

Which of the following lack seeds?

a. ferns
b. angiosperms
c. gymnosperms
d. fruits
e. all of the above contain seeds

Answer 57

a. ferns
- ferns are vascular plants that contain xylem and phloem tissue. They reproduce by spores. Ferns lack seeds and flowers. The life cycle is referred to as alternation of generations which include a sporophytic and gametophytic phase. Angiosperms and gymnosperms are seed-producing plants.

Question 58

Organs are constructed from which four basic tissue types?

a. adipose, nervous, epithelium, and connective tissue
b. connective tissue, muscle, nervous, and submucosa
c. adipose, mucosa, submucosa, and nervous
d. nervous, epithelium, muscle, and connective tissue
e. adipose, nervous, cartilage, and bone

Answer 58

d. nervous, epithelium, muscle, and connective tissue

Question 59

What is the reproductive structure of an angiosperm?

a. flower
b. rhizoid
c. pine cone
d. pollen
e. archegonia

Answer 59

a. flower
- angiosperms are the flowering plants which are divided into monocots and dicots. The flower is the reproductive structure of an angiosperm.

Question 60

Which statement is false?

a. a savanna is a tropical grassland which may cover tropical and subtropical areas such as parts of Australia and Africa
b. More ungulates live in the taiga than any other biome
c. Grasslands and savannas may receive an average of 25 inches of rainfall a year to prevent the regions from turning into deserts
d. Seasonal drought, fires, and large mammals grazing may be seen in the grasslands
e. Grassland soils are among the most fertile in the world

Answer 60

b. More ungulates live in the taiga than any other biome

- ungulates are large-hooved plant-eating mammals such as giraffes seen in the African savanna.

Question 61

According to the ….effect, deoxygenated hemoglobin has a greater affinity for CO2 than does oxyhemoglobin.

a. Bohr
b. Haldane
c. Carboxy
d. Dalton
e. Sanders

Answer 61

b. Haldane

Question 62

Which is incorrectly matched?

a. xylem: no nucleus when mature
b. sieve tube cells: no nucleus; food-conducting cell
c. parenchyma cells: no nucleus, carry metabolic fxns
d. secodnary xylem: make up most of wood of a tree
e. stomata: pores on leaf surface, fxn in gas exchange

Answer 62

c. parenchyma cells: no nucleus, carry metabolic fxns
- mature xylem and sieve tube cells have no nucleus. the sap of a plant is transported by sieve tube cells. parenchyma cells carry out metabolic fxns such as synthesis of organic compounds. The photosynthetic cells in a leaf are actually parenchyma cells. Parenchyma cells do have a nucleus. Secondary xylem makes up most of the wood in a tree. CO2 enters the leaf and oxygen exits by the stomata.

Question 63

Which of the following is incorrectly matched?

a. cnidaria: hydras, corals, jellyfish
b. arthropoda: spiders and crustaceans
c. chordata: tunicates, mammlas, amphibians
d. chordata: reptiles, jawless fish
e. all are correct

Answer 63

e. all are correct

- important question. memorize all.

Question 64

Which statement is false?

a. nissl bodies are areas of rough endoplasmic reticulum
b. microglia are phagocytic cells of the CNS
c. during the refractory period following an action potential, the sodium gates are closed.
d. a membrane will not respond to any other stimulus, no matter how strong during the absolute refractory period
e. inactivation of potassium channels is responsible for the absolute refractory period

Answer 64

e. inactivation of potassium channels is responsible for the absolute refractory period
- inactivation of sodium channels is solely responsible for the absolute refractory period—> no action potential possible
- nissl bodies are rough endoplasmic reticulum and are involved in neuron protein synthesis.
- microglia are the “residet” macrophages of the CNS.

Question 65

Which statement is false?

a. t-RNA, m-RNA, r-RNA are produced in transcription
b. a 5’ACATCG3’ DNA strand is complementary to a 3’UGUAGC5’ strand
c. RNA polymerase will proofread in a similar fashion as DNA polymerase
d. at least one t-RNA binds specifically to each of the 20 amino acids, and often there are several t-RNA molecules for an amino acids
e. t-RNA will have “cloverleaf” structure

Answer 65

c. RNA polymerase will proofread in a similar fashion as DNA polymerase
- RNA polymerase does not have proofreading ability. Therefore, RNA synthesis has a greater error level than that of DNA.

Question 66

307. Which statement is true?
     a. angiosperms are the most diverse types of plants: they are the flowering plants
     b. a cotyledon or so-called seed leaf will store food for the germinating seedling
     c. endosperm will serve as food for a flowering plant embryo, and later for the germinating seedling
     d. vegetative propagation is a form of asexual reproduction in plants.
     e. all are true

Answer 66

e. all are true

Question 67

Which statement is false?

a. urine is hypertonic to blood and contains a high urea and solute concentration
b. combination of passive diffusion and active transport in the loop of henle of solutes helps in the conservation of water
c. ADH will allow water to be reabsorbed at the distal tubules and collecting ducts when water conservation is needed
d. HCO3-, bicarbonate ion is the form in which CO2 is carried predominantly in the blood.
e. Humoral immunity involves T-lymphocytes

Answer 67

e. Humoral immunity involves T-lymphocytes
- humoral immunity is responsible for the production of immunoglobins or antibodies—> bind antigen (foreign) and destroy it.
- T-lymphocytes are involved in cell-mediated immunity. They do not produce antibodies, B lymphocytes produce antibodies.

Question 68

Which statement is false?

a. an amphibian is a vertebrate that is able to live on land and water
b. the amphibian has a closed circulatory system
c. at end of gastrulation -> ectoderm, mesodem, endoderm
d. NH3 is most abundant waste product of metabolism
e. all are correct

Answer 68

d. NH3 is most abundant waste product of metabolism
(false)

• CO2 is the most abundant waste product.

Question 69

An 11 year old boy is taken to the doctor because he has a fever and malaise. Which cell would likely be increased if the child has a bacterial infection?

a. red blood cells
b. neutrophils
c. mast cells
d. platelets
e. basophils

Answer 69

b. neutrophils
- principal innate immune system cell is the neutorphil, which is the most numerous of the white blood cells and is directly involved in combating bacterial infections. B
- Basophils contain histamine, heparin, and several cytokines.

Question 70

Which organ contains a surplus of red blood cells which may be needed for an emergency situation?

a. liver
b. spleen
c. colon
d. kidneys
e. pancreas

Answer 70

b. spleen
- spleen is similar in structure to a large lymph node. This organ removes old worn out red blood cells and carries a reserve of blood which can be utilized for emergency situations.

Question 71

Mycology is a branch of science that studies fungi. The three major divisions are based on?

a. mode of nutrition
b. type of sexual spored they reproduce
c. cell wall composition
d. hyphae composition
e. mycelium number

Answer 71

b. type of sexual spored they reproduce
- placement is based on the way the fungus reproduces. When a sexual phase can’t be detected or is absent from the life cycle, the term “imperfect” fungi is assigned.

Question 72

which serves as a rapidly available reserve of high-energy phosphates in skeletal muscle?

a. ADP
b. GTP
c. Creatine Phosphate
d. Glucose-6-phosphate
e. Fructose-6-phosphate

Answer 72

c. Creatine Phosphate
- phosphocreatine (or creatine phosphate) provides a quick energy source for skeletal muscles when they need an initial energy burst.

Question 73

Which came first?

a. reptiles
b. amphibians
c. bony fish
d. jawless fish
e. cartilaginous fish

Answer 73

d. jawless fish

- jawless fish include hagfish and lampreys.

Question 74

The most diverse and abundant vertebrates include:

a. bony fish
b. birds
c. amphibians
d. mammals
e. reptiles

Answer 74

a. bony fish
- the swim bladder of modern bony fish was modified from simple lungs and is involved in the control for buoyancy of the fish. glands in the skin of bony fish secrete mucus, which gives the fish a slimy feel.

Question 75

During denaturation of a protein there is a change in:

a. 1 structure
b. 2 and 3 structure
c. 2, 3, and 4 structure
d. 1 and 2 structure
e. 1, 2, 3, and 4 structure

Answer 75

c. 2, 3, and 4 structure
- the primary structure is lost only if digestion (hydrolysis) occurs. heat, pH change, radiation, heavy metals such as Pb+2, Ag+ and Hg+2 may cause denaturation of a protein.

Question 76

where is bile produced?

a. pancreas
b. liver
c. gall bladder
d. kidney
e. adrenal glands

Answer 76

b. liver
- bile, an emulsifier of fats, is produced in the liver, and stored in the gall bladder.
- urea formation occurs primarily in the liver as well.

Question 77

Where is pollen produced?

a. pistil
b. stamen
c. petal
d. anther
e. ovary

Answer 77

d. anther
- a pollen grain is an immature male gametophyte with a hard covering. The anther is the chamber where pollen develops.
- Pistil is the female part of the plant: consists of stigma, style, and ovary. stigma is sticky and will catch the pollen: the style is a tube-like structure connecting the stigma to ovary. The ovary encloses one or more ovules where the monoploid egg nucleus is found.

• The stamen is the male part of the plant.
• anther + filament = stamen
• The petal is the colorful part of the plant that attracts insects, they have odors as well.
• In plants, the haploid gametophyte is multicellular, while in animals it is unicellular.

Question 78

Which is a false statement?

a. collagen is found in the extracellular matrix
b. collagen is a fibrous protein w/ a triple helix
c. myoglobin exists as a tetramer, and will store O2 in muscle
d. platelets do not contain a nucleus
e. an osteoblast will create new bone

Answer 78

c. myoglobin exists as a tetramer, and will store O2 in muscle

• myoglobin consists of a single chain, but does store O2 in muscle.
• hemoglobin, another globular protein consists of two alpha chains and two beta chains.
• extracellular matrix is rich in collagen

Question 79

Which statement is false?

a. acetylcholine is the primary neurotransmitter of the parasympathetic nervous system
b. norepinephrine is the primary neurotransmitter of the sympathetic nervous system
c. acetylcholine has excitatory and inhibitory effects on muscles and glands throughout the body
d. an action potential is an all-or-nothing event
e. all are true statements

Answer 79

e. all are true statements

- AP NS

Question 80

Which statement is false?

a. differentiation occurs when a cell has become specialized
b. differentiation will arise as a result of selective gene expression
c. an annelid has a closed circulatory system
d. an arthropod has an open circulatory system
e. nematodes are the segmented worms

Answer 80

e. nematodes are the segmented worms (false)
- annelids are the segmented worms
- Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. The open circulatory system is common to molluscs and arthropods.

Question 81

Which antibody class can significantly cross the human placenta?

a. IgG
b. IgA
c. IgM
d. IgD
e. IgE

Answer 81

a. IgG
- IgG is the class of antibody that is found in the highest concentration in the blood, as well as the only one that can significantly cross the human placenta. Interestingly, human milk is most rich in IgA, which plays a role in microbial infection prevention in infants.

Question 82

Which statement is false?

a. The three principal fibers in connective tissue are reticular, elstin and collagen
b. ground substance is the gel-like noncellular portion of the extracellular matrix where fibers and connective tissue cells are located
c. ground substance is produced by the fibroblasts
d. osteocytes make up the ground substance which contains fibers and connective tissue
e. ground substance contains H2O, glycosaminoglycans, proteoglycans, and glycoproteins

Answer 82

d. osteocytes make up the ground substance which contains fibers and connective tissue (false)
- osteocytes are entrapped in the bone matrix and are involved in regulating bone health.
- ground substance is the gel-like noncellular portion of the extracellular matrix. Fibers, glycoproteins, proteoglycans, and glycosaminoglycans can be found
- fibroblasts produce the ground substance, not osteocytes.

Question 83

Which is false about cephalopods?

a. cephalopods have tentacles to capture prey
b. cephalopods include the squid; the largest known invertebrate
c. cephalopods have little oxygen demand
d. cephalopods contain a well developed nervous system
e. giant nerve fibers connect the brain with muscles used in jet propulsion

Answer 83

c. cephalopods have little oxygen demand (false)

• cephalopods are highly active and have huge oxygen demands.
• cephalopods have a closed circulatory system and mollusks have an open circulatory system

Question 84

Which statement is false?

a. the shape of the t-RNA is maintained by H bonds
b. 3 nucleotides specify one of 20 common amino acids
c. translation refers to the synthesis of proteins
d. DNA sequences that appear to move from one part of the genome to another are called transposable elements
e. m-RNA may contain some unusual bases such as methylinosine

Answer 84

e. m-RNA may contain some unusual bases such as methylinosine (false)
- a distinguishing feature of t-RNA is the presence of unusual bases such as methylinosine, pseudouridine, and 4-thiouridine.

Question 85

Which of the following are in Kingdom Monera?

a. Paramecium
b. Mushroom
c. Bacteria
d. Green algae
e. More than one of these

Answer 85

c. Bacteria

• paramecium -> protista
• mushroom -> fungi
• green algae -> protista
• blue-green algae -> monera

Question 86

343. Which phylum is incorrectly matched?
     a. nematoda: hookworms and pinworms
     b. Platyhelminths: tapeworms and flukes
     c. Annelida: leeches and earthworms
     d. Echinodermata: sea urchins, sea stars
     e. Mollusca: corals and sea anemones

Answer 86

e. Mollusca: corals and sea anemones (false)

• all are important to know
• mollusca -> snails, slugs, clams, and octopuses
• cnidaria -> corals and sea anemones
• annelida -> segmented worms

Question 87

344. Which statement is false?
     a. the tunicate (sea squirt) is a chordate, but an invertebrate
     b. Echinoderms do not have a notochord during any developmental stage
     c. Blastopore always forms the mouth before anus
     d. Malpighian tubules of insects form uric acid and discharge it into gut
     e. Functional unit of excretion in earthworms is nephridium

Answer 87

c. Blastopore always forms the mouth before anus (false)
- Echinoderms and chordates are deutrostomes -> mouth formed after anus from blastopore. In all other organisms, blastopre will form the mouth first.

Question 88

345. Which of the following is matched correctly?
     a. Bryophytes: mosses
     b. Bryophytes: non-vascular plants
     c. Angiosperms: flowering plants
     d. Sporazoans: plasmodium
     e. All are correctly matched

Answer 88

e. All are correctly matched
- non-vascular bryophytes include mosses, liverworts, and hornworts. They have underground stems and live in moist, humid habitats.
- Angiosperms are the flowering plants that include monocots and dicots
- Sporazoans are a diverse group of parasites that include the plasmodium. Plasmodium casues malaria. Mosquitoes transmit them to birds or humans

Question 89

346. Which is true about bone?
     a. Arm bones include humerus, ulna, and radius
     b. Leg bones include fibula, tibia, and femur
     c. Osteoblasts: bone-forming
     d. Osteoclasts: bone-resorbing
     e. All are true

Answer 89

e. All are true
- Bone consists of living cells and collagen fibers. A distinguishing feature is its extracellular matrix of collagen fibers and ground substance. Glycoproteins and fibrous proteins for the “jelly like” ground substance
- Inside bones is a soft connective tissue called marrow. Marrow is found in irregular spaces of spongy bones, medullary cavitites of long bones, and in haversian canals. Red marrow -> RBC formatio, certain WBCs and platelets; Yellow marrow -> mostly fat
- Most mature bones contain yellow marrow, which can be converted to red marrow when blood loss is severe
- Areas of contact or “near-contact” between bones are called joints. Joints are stabilized by ligaments. As a person ages, cartilage that covers bone ends of freely movable joints begins to wear away -> osteoarthritits. Rheumatoid arthritis is a degenerative disorder w/ a genetic basis.

Question 90

347. All of the following are true about bone except?
     a. Bone contains blood and nerves
     b. Triglycerides are contained in yellow bone marrow
     c. Ground substance and collagen are a distinguishing feature of bone
     d. Haversian canals are interconnected channels for blood vessels and nerves
     e. Trapped osteoblasts within the small spaces of bone mature into fibroblasts

Answer 90

e. Trapped osteoblasts within the small spaces of bone mature into fibroblasts (false)
- Once trapped in small spaces of bone, osteoblasts -> osteocytes (living bone cells).
- Fibroblasts produce extracellular fibers and ground substance of connective tissue. Collagen is made by the fibroblasts as well

• *Review of more cells:
• RBC: O2 transport
• WBC: infections
• Macrophage and neutrophils (most common WBC, bacteria infection): phagocytosis
• Plasma cells: antibody production
• Mast cells: histamine release

Question 91

348. An amnion is present in all of the following except:
     a. Pigeon
     b. Turtle
     c. Frog
     d. Man
     e. Lizard

Answer 91

c. Frog
- Amnion is a fluid-filled sac that surround the embryo in reptiles, birds, and mammals. An amphibian, such as a frog does not have an amnion.
- Allantois is also only found in reptiles, birds, and mammals.

Question 92

350. If 36% of a population has blue eyes, what is the percentage of the recessive allele?
     a. 60 %
     b. 64 %
     c. 36 %
     d. 50 %
     e. 0 %

Answer 92

a. 60 %

- Blue eyes are homozygous recessive

Question 93

351. Which of the following is false?
     a. Most abundant RNA = r-RNA
     b. Least abundant RNA = m-RNA
     c. Smallest of RNA = t-RNA
     d. Several t-RNA can exist for an amino acid
     e. None of these are false

Answer 93

e. None of these are false

• m-RNA turns over rapidly = lest abundant
• sequence of three bases in mRNA is codon, t-RNA triplet that H bonds to codon is anticodon.

Question 94

353. Which of the following is not associated with fungi?
     a. Zygomycetes
     b. Basidiomycetes
     c. Lichen
     d. Ascomycetes
     e. All are correct

Answer 94

e. All are correct

• Lichen = symbiosis of fungi and blue-green algae
• A, B, and D are names of fungi groups

Question 95

354. The amount of blood in an average-sized adult is approximately:
     a. 3 quarts
     b. 5 quarts
     c. 11 quarts
     d. 15 quarts
     e. 20 quarts

Answer 95

b. 5 quarts

• Blood is a tissue that carries raw materials, wastes, and substances to and away from cells. Plasma is the liquid portion of the blood and contains hundreds of plasma proteins such as albumin, fibrinogen, and globulin.
• Albumin is the most abundant, and is important for maintaining the blood’s osmotic pressure.

Question 96

355. Which statement is false?
     a. Blood clotting involves a series of chain reactions in which fibringoen is converted into fibrin
     b. Fibrin fibers form a “mesh” that traps red blood cells to become a solid barrier to blood loss
     c. Unlike other blood cells, WBCs can leave the blood vessels and circulate in the lymphatic system
     d. In a typical antibody, the heavy and light chains are linked by H bonds
     e. All are correct

Answer 96

d. In a typical antibody, the heavy and light chains are linked by H bonds (false)
- Antibodies (immunoglobins) consist of two heavy chains linked to two light chains by disulfide bonds. The disulfide bond (-S-S-) is seen in many proteins such as antibodies, hair, and insulin. Disulfide bonds restrict the way the protein can fold. The disulfide is a covalent bond.

Question 97

357. On a per gram basis, which contains the greatest amount of energy?
     a. Vitamin C
     b. Vitamin B
     c. Fat
     d. Protein
     e. Carbohydrate

Answer 97

c. Fat
- Fats yield more than twice the energy than a protein or a carbohydrate. Vitamins will not yield any energy.

• Vitamins B,C –> H2O soluble
• Vitamins A, D, E, K —> fat soluble (FAT nAKED guy on the beach)

Question 98

360. Which statement is false?
     a. The savanna is a grassland with low rainfall and punctuated with hooved, plant-eating mammals such as giraffes
     b. the tundra will exhibit a treeless frozen plain with a permafrost
     c. In a desert, the potential for rainfall is greater than the potential for evaporation
     d. Biome is a particular type of regional ecosystems that is dominated by certain plants and animals
     e. Oceans cover more than 70% of Earth’s surface

Answer 98

c. In a desert, the potential for rainfall is greater than the potential for evaporation (false)
- Desert: potential for evaporation is much greater than the potential for rainfall.

Question 99

361. Which statement is true?
     a. During evolution, several different well-protected species have come to resemble one another in what is called Mullerian mimicry
     b. A bird will avoid a red colored insect with white stripes after two insects have stung it. This is an example of Mullerian mimicry
     c. Plants may contain tannin, which imparts an unsatisfactory taste to leaves and twigs, thus will discourage herbivores from consuming them.
     d. Unpalatable prey is often highly colored, which can warn predator that such organisms should be avoided.
     e. All are true

Answer 99

e. All are true
- Mullerian mimicry: same colors, but not phylogenetically related, predator won’t attack since they all look alike
- Batesian mimicry: deceptive mimicry, a harmless fly resembles one that is dangerous

Question 100

362. Which statement is false?
     a. B cells are lymphocytes that mature in bone marrow and mediate antibody directed immunity
     b. Stem cells in bone marrow produce lymphocytes by meiosis
     c. Antibodies are produced by B cell can can bind antigens
     d. In cell-mediated immunity, T cells respond to virally infected cells, fungi, parasites and bacteria
     e. All are true

Answer 100

b. Stem cells in bone marrow produce lymphocytes by meiosis (false)
- Stem cells in bone marrow produce lymphocytes by mitotic division.
- Immunity results from production of antibodies which are proteins.

• Two types of Immunity:
  1. Antibody-mediated immunity: B cells
  2. Cell-mediated immunity: T cells (mature in thymus)

Question 101

363. The Hershey- Chase experiment confirms that DNA is the genetic material using bacteriophages. The use of which two are radioactive labels?
     a. Nitrogen and carbon
     b. Sulfur and oxygen
     c. Phosphorus and sulfur
     d. Hydrogen and phosphorus
     e. Sulfur and samarium

Answer 101

c. Phosphorus and sulfur
- Experiment used radioactive 35S and 32P. Phages labeled with 35S (protein) and 32P (DNA) were allowed to infect E.coli. After infection, the viruses and their host cells were mechanically separated in a blender. Labeled DNA was found in host cell, while labeled protein was found mostly outside —> DNA is genetic information.

Question 102

364. Which statement is false?
     a. Emphysema is a pathology marked by destruction of alveoli
     b. Ciliated pseudostratified columnar epithelial cells are found in trachea and upper respiratory system
     c. Pseudostratified columnar epithelial cells may contain goblet cells which secrete mucous
     d. Smoking can damage the cilia of respiratory cells and allow toxins to remain in lungs
     e. Smoking will cause a decrease in mucous as a response to the irritant

Answer 102

e. Smoking will cause a decrease in mucous as a response to the irritant (false)
- Response to smoking -> cilia damaged and mucous produced by goblet cells is increased. The lungs have a decreased means of moving the mucous out, thus an unproductive cough results. Continued smoking may lead to chronic bronchitis, emphysema, or lung cancer.

Question 103

365. ATP —-> ADP, What type of reaction is this?
     a. Reduction
     b. Hydrolysis
     c. Oxidation
     d. Dehydration
     e. Synthesis

Answer 103

b. Hydrolysis

Question 104

366. The disaccharide lactose is made from glucose and galactose. The process by which lactose is made is called?
     a. Hydrolysis
     b. Dehydration synthesis
     c. Reduction
     d. Phophorylation
     e. Lactation

Answer 104

b. Dehydration synthesis
- monomers are joined in condensation reactions which are also called dehydration synthesis. Water is lost in process.

• Lactose: glucose + galactose (milk)
• Sucrose: glucose + fructose (table sugar)
• Maltose: glucose + glucose

Question 105

367. Human oocytes can be fertlized most successfully by the us of which technique?
     a. Micor-injection
     b. In-vitro fertilization
     c. Ligation
     d. Amniocentesis
     e. Karyotyping

Answer 105

a. Micro-injection
- In-vitro fertilization -> egg and sperm in a glass dish in lab.
- Micro-injection -> directly injecting sperm cell into egg. Average success rate about 75 %.

Question 106

368. The promoter region in eukaryotes which contain a group of nucelotides is called a:
     a. Operon
     b. TATA box
     c. Exon
     d. Operator
     e. Pribnow box

Answer 106

b. TATA box
- Promoter sites bind RNA polymerase and determine where transcription begins.
- In prokaryotes, the sequence is called a Pribnow box, while in eukaryotes it is called a TATA box. These regions are very rich in adenine and thymine.

Question 107

369. Which statement is false?
     a. The assemblage of operator, promoter, and structural genes is called an operon
     b. An operator is the site to which a repressor of protein synthesis binds
     c. The operator is the control point for translation
     d. A repressor binds to operator and will block RNA polymerase attachment to promoter, thus stopping transcription
     e. RNA polymerase binds DNA regions called promoters

Answer 107

c. The operator is the control point for translation

- Operator is control point for transcription, not translation.

Question 108

370. Which are correctly matched?
     a. IgD, IgA, IgM, IgE, IgG are the 5 classes of immunoglobins
     b. Helper T cells refer to a type of lymphocyte that stimulates the production of antibodies by B cells when an antigen is present
     c. Antigenic determinant is site on an antigen to which an antibody binds, thus forming an antigen-antibody complex
     d. Two of above
     e. All of above

Answer 108

e. All of above
- There are several types of T cells which include killer T cells, suppressor T cells and memory cells.
- Large WBCs derived from monocytes are called macrophages. The macrophage will engulf antigen and present it to the T-cells that will activate the immune response.

Question 109

371. Which is true about Erythroblastosis fetalis?
     a. Rh+ fetus; Rh+ mother
     b. Rh- fetus; Rh+ mother
     c. Rh- fetus; Rh- mother
     d. Rh+ fetus; Rh- mother
     e. none of the above

Answer 109

d. Rh+ fetus; Rh- mother
- Rh refers to blood group. Rh+ means you have the ability to produce the Rh antigen, while Rh- means you lack Rh antigen production ability. In erythroblastosis fetalis, an Rh- mother has a fetus that is Rh+. In such cases, the mother produces antibodies (during birth, baby’s blood may enter mother’s blood). If she later carrers another Rh+ fetus, her Rh antibodies will diffuse across placenta and cause blood cells to agglutinate and fetal blood cells are consequently destroyed.

Question 110

372. An egg cell will contain?
     a. 23 chromosomes, 46 chromatids
     b. 23 chromsomes, 23 chromatids
     c. 46 chromosmes, 46 chromatids
     d. 46 chromosomes, 46 chromatids
     e. 48 chromosomes, 24 chromatids

Answer 110

b. 23 chromsomes, 23 chromatids

- both egg and sperm are haploid.

Question 111

376. A chemical defense system that works with the immune response and supplements the inflammatory response is termed:
     a. antibody-mediated immunity
     b. antigen
     c. complement
     d. cell recognition
     e. antigenic determinant

Answer 111

c. complement
- the “complement” system is actually a chemical defense system designed to destroy microogranisms. It complements the immune system, and is comprised of a complex series of serum proteins.

Question 112

377. A(n)…….is created by the fusion of normal haploid gametes from different but closely related species.
     a. Monosomic
     b. Allodiploid
     c. Aneuploid
     d. Autodiploid
     e. Myeloma

Answer 112

b. Allodiploid
- A cell that has two genetically distinct sets of chromosomes that are derived from different ancestral species is termed Allodiploid. If the cell has two genetically identical or nearly identical chromosmes sets derived from the same ancestral species, it is termed Autodiplid.
- seen in animals but far more common in plants.

Question 113

379. The briefest mitotic stage is:
     a. Telophase
     b. Interphase
     c. Metaphase
     d. Anaphase
     e. All are approximately equal

Answer 113

c. Anaphase

Question 114

381. The formation of new species due to geographical isolation is called:
     a. Allopatric speciation
     b. sympatric speciation
     c. Mutaton
     d. Polyploidy
     e. None of these

Answer 114

a. Allopatric speciation

Question 115

383. When O2 binds to hemoglobin, we see an increased affinity for O2 binding in the remaining subunits. This is called:
     a. cooperativity
     b. Complement
     c. Competitive inhibition
     d. Allosteric effect
     e. None of these

Answer 115

a. cooperativity
- Hemoglobin is an allosteric molecule with more than one binding site. When first O2 binds, many salt bridges are broken or disturbed upon binding. The consequence of this is a conformational change in the molecule, and additional O2 can more easily bind.

Question 116

384. Which are incorrectly matched?
     a. Green Algae: Spirogyra
     b. Red Algae: Rhodophyta
     c. Bryophytes: Moss
     d. Nematoda: Roundworms
     e. Platyhelmint: Earthworms

Answer 116

e. Platyhelmint: Earthworms (false)

• Earthworm = Annelida
• Flatworms = Platyhelminthes

Question 117

385. Which statement is false?
     a. cephalizatoin refers to having sensory structures and nerve cells mainly up front, in a head
     b. Mollusks, arthropods, and annelids are protostomes
     c. Echinoderms and chordates are deuterostomes
     d. In protostomes, the opening of the first indentation becomes the mouth
     e. All are correct

Answer 117

e. All are correct

-

Question 118

386. Which statement is incorrect?
     a. if an organism is too warm, blood vessels will dilate.
     b. If an organism is too cold, the blood vessels will constrict
     c. The oncotic pressure tends to pull fluid into capillary
     d. The hydrostatic pressure tends to push fluid out of a capillary
     e. All are correct

Answer 118

e. All are correct
- By using thermoregulation, organisms can control flow of blood to the skin. If too warm, blood vessels dilate to allow heat to escape. If too cold, heat loss is reduced since the vessels will constrict.

Question 119

387. Which statement is false?
     a. A zymogen is an inactive form of an enzyme
     b. Estrogen is a steroid hormone, while insulin is a peptide hormone
     c. Endocytosis, like active transport requires ATP
     d. Steroid hormone receptors usually occur within the cell rather than part of the membrane
     e. All are correct

Answer 119

e. All are correct

- Zymogen such as pepsinogen is the inactive form of an enzyme.

Question 120

388. Which is incorrectly matched?
     a. Spherical bacteria : cocci
     b. Rod shaped bacteria: Bacilli
     c. Helical shaped bacteria: Spirilla
     d. Staphylococci: clusters
     e. Streptococci: non-virulent

Answer 120

e. Streptococci: non-virulent (false)
- Streptococi may indeed be virulent and kill an organism. The streptococci form chains, while the staphylococci form cluster.

• Strep = strip
• Staph = stuff

Question 121

389. Which statement is false?
     a. lymph nodes may contain lymphocytes and macrophages
     b. plasma cells produce antibodies
     c. The greatest resistance to blood flow is in the arterioles
     d. In the normal adult, there are 8 premolars
     e. All are true

Answer 121

e. All are true

Question 122

391. Cytochromes are associated with which of the following?
     a. TCA cycle
     b. Glycolysis
     c. Gluconeogenesis
     d. Electron transport chain
     e. None of theses

Answer 122

d. Electron transport chain

- Cytochroms are a group of heme containing proteins found in the e- transport chain

Question 123

392. Which are the most recent?
     a. Cenzoic
     b. Mesozoic
     c. Paleozoic
     d. Precambian
     e. Achaean

Answer 123

a. Cenzoic

Cenzoid (most recent) > Mesozoic > Paleozoic > Precambian (oldest)

• Dinosaurs appeared during Mesozoic era
• First land vertebrates, land plants, fish: many alga appeared in Paleozoic era
• Invertebrates, monera, fungi were in precambrian (earliest) era

Question 124

393. “Ontogeny recapitulates phylogeny” refers to:
     a. phylum relations between organisms
     b. The founder effect
     c. Embryonic stages of development of an organism repeat the evolutionary history of the species
     d. Embryonic stages of development of an organism pass through similar stages in other vertebrates
     e. two of the above

Answer 124

c. Embryonic stages of development of an organism repeat the evolutionary history of the species
- This notion has not been accepted in modern evolutionary theory.

Question 125

394. Shrinkage of a cell due to water loss is called:
     a. Hydrolysis
     b. Osmosis
     c. Plasmolysis
     d. Difusion
     e. Active Transport

Answer 125

c. Plasmolysis

- In a hypertonic solution, a cell will shrink; this is called plasmolysis.

Question 126

397. Which statement is incorrect?
     a. The earliest organisms were probably heterotrophs
     b. Obligage anaerobes cannot survive in an atmosphere of oxygen
     c. Peptidoglycans contain amino sugars
     d. Halophiles are bacteria that live in extemely salty water
     e. Purple or green bacteria are photosythetic bacteria in which Oxygen is the by-product

Answer 126

e. Purple or green bacteria are photosythetic bacteria in which Oxygen is the by-product
- Purple or green bacteria found in anaerobic sediments of lakes or ponds carry out photosynthesis in which H2, H2S, or D is the electron donor, oxygen is not a by-product.

Question 127

398. DNA is not found in:
     a. Erythrocytes
     b. Lymphocytes
     c. Skin cells
     d. Hair cells
     e. Sperm cells

Answer 127

a. Erythrocytes

- An erythrocyte (RBC) lacks a nucleus, thus contains no DNA.

Question 128

399. Which statement is false?
     a. Hemoglobin gives up more O2 under acidic conditions
     b. Hemoglobin is a tetramer, while myoglobin is a monomer
     c. The heme group is the same in both hemoglobin and myoglobin
     d. Oxygen binding to hemoglobin is cooperative
     e. Disulfide bridges are broken during allosteric interactions

Answer 128

e. Disulfide bridges are broken during allosteric interactions
- During allosteric interaction, when a molecule binds, a conformational change occurs and the primary binding site will no longer bind to its usual substrate.
- In the Bohr Effect, we see hemoglobin-unloading O2 under conditions of low ph (high CO2 (H+))

Question 129

400. The Zona Fasciculata:
     a. Constitutes the middle zone of the adrenal cortex
     b. Produes the glucocoricoid cortisol
     c. Represents the inner most cortical layer
     d. B and C only
     e. A and B only

Answer 129

e. A and B only

• Zona Fasciculata constitutes the middle zone of the adrenal cortex and produces the glucocorticoid cortisol.
• The innermost cortical layer is called the zona reticularis and produces androgens, the precursors to testosterones in humans.
• The zona glomerulosa produces the mineralcorticoids, such as aldosterone.

Question 130

401. Which of the following is called a “second messenger”?
     a. ADP
     b. ATP
     c. Cyclic AMP
     d. NAD+
     e. FADH2

Answer 130

c. Cyclic AMP
- Most of the protein hormones and polypeptide hormones act by way of cyclic AMP. Thy cyclic AMP activates enzymes, initiates protein synthesis, and can even alter membrane permeability.

Question 131

402. Which statement(s) is true?
     a. Monnocots and dicots differ in the arrangement of vascular bundles
     b. Monocots contain one cotyledon
     c. Dicots contain two cotyledons
     d. In monocots, leaf veins run parallel, whereas in dicots they run netlike
     e. All of the above are true

Answer 131

e. All of the above are true
- Important point here is arrangement of vascular bundles. A vascular bundle is a multistranded cord of phloem and xylem tissue. In the dicots, the vascular tissues are arranged around a central core in the system. In monocots, they are scattered.

• Monocots: one cotyledon, fibrous roots, scattered vascular bundles, parallel veins (leaf), flowers are multiples of 3
• Dicots: two cotyledon, tap roots, ringed vascular bundles, net-like veins (leaf), 4 or 5 flowers.

Question 132

403. A zymogen is an inactive precursor of an enzyme which may become activated. Which best describes the likely mode of this activation?
     a. ATP is added to the zymogen which allows for an endergonic process to become exergonic
     b. Disulfide bridges are redued to mercaptan groups which can act as nucleophiles
     c. Denaturation occurs; this casues a conformational change
     d. Cleavage of one or more peptide bonds catalyzed by an enzyme
     e. Salt bridge cleavage resulting in less charge, thus changing the conformation

Answer 132

d. Cleavage of one or more peptide bonds catalyzed by an enzyme
- Trypsin and Chymotrypsin provide a fine example of zymogen activation. Activation of their precursors occurs by cleavage of peptide bonds using enzymes.

Chymotrypsingoen —–trypsin (cleavage of peptide bonds)—»»> chymotrypsin

Trypsinogen—-enterokinase (cleavage of peptide bonds)—–»»> Trypsin

Question 133

404. A scientist identified glycosidases, aryl sulfatases, and a phosphatase. Where would these most likely be found?
     a. Ribosomes
     b. Lysosomes
     c. Vacuoles
     d. Mitochondria
     e. Nucleolus

Answer 133

b. Lysosomes

- Lysosomes are involved in the digesting of substances brought into the cell and contain many enzymes.

Question 134

405. Which is not a protist?
     a. Algae
     b. Bacterium
     c. Euglena
     d. Paramecium
     e. All of the above are protists

Answer 134

b. Bacterium
- Protists are eukaryotic organisms such as hydra, paramecium, euglena and algae. All protists live in moist environments.
- Bacteria are prokaryotes that are in kingdom Monera.

Question 135

406. Which statement is false?
     a. Mendel proposed the Law of Independent Assortment
     b. According to Mendel’s Law of segregation, the two genes segregate from each other at meiosis, thus each gamete produced after meiosis has an equal chance of receiving one or the other gene, but not both
     c. Each pair of alleles segregates into gametes independently according to Mendel’s Law of Independent Assortment
     d. A 9:3:3:1 phenotypic ratio is characteristic of the F1 generation of a dihybrid cross
     e. A mother of blood type AB marries a father with type O blood. The children can have either type A or Type B blood types.

Answer 135

d. A 9:3:3:1 phenotypic ratio is characteristic of the F1 generation of a dihybrid cross (false)
- A 9:3:3:1 phenotypic ratio is characteristic of the F2 generation.

Question 136

409. Which is true regarding pheromones?
     a. It is a chemical that travels outside the body, carrying information to members of same species
     b. They may act as “sex attractants”
     c. Formic acid produced by ants is an example of a pheromone
     d. Many vertebrates use pheromones in feces, urine or scent glands to mark territories.
     e. All of these are true

Answer 136

e. All of these are true

Question 137

413. A person who has recently undergone an organ transplant presents with rejection of the transplanted organ. Which is most responsible for stimulating the rejection of the organ?
     a. Basophils
     b. Neutrophils
     c. Major Histocompatibility Complex
     d. Lysosomes
     e. Histamine

Answer 137

c. Major Histocompatibility Complex
- MHC is important in distinguishing self from nonself. MHC triggers T cells to attack and begin a cell-mediated response against the donated organ.

Question 138

415. Which technique is most widely used to elucidate the three-dimensional structure of a macromolecule?
     a. X-Ray crystallography
     b. Electrophoresis
     c. IR spectroscopy
     d. UV-Spectroscopy
     e. Denaturation

Answer 138

a. X-Ray crystallography

Question 139

416. Which statement is incorrect?
     a. GABA is the major inhibitory brain neurotransmitter
     b. It is at the presynaptic membrane where we see synaptic vesicles discharge their contents by a process called exocytosis
     c. Serotonin is a neurotransmitter that may play a role in mood swings
     d. CSF cushions the brain and transports nutrients and hormones within the brain
     e. The blood-brain barrier allows for the passage of most drugs, ions, and pathogens into the CNS so they can be phagocytized by the WBCs

Answer 139

e. The blood-brain barrier allows for the passage of most drugs, ions, and pathogens into the CNS so they can be phagocytized by the WBCs (false)
- It is actually a barrier against these substances. It is however, permeable to O2, CO2, glucose and general anesthetics.

Question 140

417. Which statement is false?
     a. Lactate is produced in a fatigued muscle.
     b. Fermentation utilizes the reactions of glycolysis to produce ethanol anaerobically
     c. Under aerobic conditions, most of the pyruvate from glycolysis is oxidized by the TCA cycle
     d. Actively contracting muscle has a high rate of pyruvate formation
     e. In yeast cells that grow anaerobically, pyruvate is converted into ethanol

Answer 140

d. Actively contracting muscle has a high rate of pyruvate formation (false)
- actively contracting muscle has a high rate of lactate formation.

Question 141

421. If a cell is attacked by a virus, which protein is produced by an animal cell in response?
     a. Albumin
     b. Collagen
     c. Interferon
     d. Thyroxin
     e. Carboxypeptidase

Answer 141

c. Interferon
- Interferons are a group of small proteins made by most body cells following a viral attack. Interferons belong to a class of glycoproteins called cytokines. Interferons are also produced in response to bacterial, parasitic, and foreign agents, as well as tumor cells.

Question 142

423. The left atria and left ventricle are connected by:
     a. Tricuspid valve
     b. Mitral valve
     c. Aortic valve
     d. Semilunar valve
     e. The coronary sinus

Answer 142

b. Mitral valve

• Tricuspid valve = right atria + right ventricle
• Mitral (bicuspid) valve = left atria + left ventricle
• Semilunar valves = aortic valve, pulmonary valve
• Coronary sinus is a wide venous channel that receives blood from the coronary veins and empties into the right atrium of the heart.
• lub dub sound: lub is closing of AV valves, dub is closing of semilunar valves

Question 143

424. The main purpose of a fungi is:
     a. Decomposition
     b. Parasitism
     c. Comensalism
     d. Chemosynthesis
     e. Photosynthesis

Answer 143

a. Decomposition

Question 144

425. Which of the following is not an example of fungi?
     a. mold
     b. mildew
     c. yeast
     d. algae
     e. mushroom

Answer 144

d. algae (false)

• algae is a protist
• blue-green algae however, are classified with moneras

Question 145

427. Which statement is false?
     a. A zygote can develop into all the types of cells and it is considered totipotent
     b. stem cells are important in therapeutic use because they can develop into many different types of tissue
     c. Totipotent cells can form all body cells as well as the extraembryonic tissues needed to form the placenta
     d. The only totipotent cells in human development are the zygote and the cells in the next few cell divisions
     e. Pluripotent cells will form every cell in the body as well as placental cell

Answer 145

e. Pluripotent cells will form every cell in the body as well as placental cell (fasle)

• Totipotent = all body cells including embryonic
• Pluripotent = all cell types, except for extra-embryonic tissue, such as the placenta

Question 146

430. Which trophic level has the least biomass?
     a. producers
     b. primary consumers
     c. secondary consumers
     d. tertiary consumers
     e. plants

Answer 146

d. tertiary consumers
- The producers represent the level of greatest biomass. Each succeeding level has less available energy due to the inability of most animals to digest cellulose.

Question 147

431. Which statement is false?
     a. Bacteria and fungi are decomposers that occupy no particular trophic level since they feed on organisms from all trophic levels
     b. The average ecological efficiency of any one trophic level is approximately 10 %
     c. Predation, competition, and available resources can all affect population size
     d. Secondary succession occurs on areas lacking in soil and have not previously supported a community
     e. The number of individuals of a species which can be sustained by resources in a given area is called carrying capacity

Answer 147

d. Secondary succession occurs on areas lacking in soil and have not previously supported a community (false)

• Primary succession occurs to areas without soil and has not previously supported a community. ex. glaciers, lava flow
• Secondary succession occurs on disturbed areas such as burned-over land. When fire sweeps through a forest, secondary succession will occur.

Question 148

432. Which statement is false?
     a. During denaturation process delta H and delta S will be positive
     b. Polar amino acid chains contain mostly oxygen and nitrogen; nonpolar amino acid side chains contain mostly carbon and hydrogen
     c. A polypeptide with 5 different amino acids can have 120 possible sequences
     d. Proteins and petroleum are polymers that could denature if heated
     e. None of these. All statements are true

Answer 148

d. Proteins and petroleum are polymers that could denature if heated (false)

• Denaturation will disrupt the 2, 3, and quaternary structure; it is endothermic and causes disorder.
• Petroleum is a mixture of hydrocarbons. Proteins are polymers of amino acids.

Question 149

433. Which is false regarding hyperthyroidism?
     a. A person may display anxiety, weakness, and increased heart rate
     b. T3 and T4 levels are elevated
     c. TSH produced by pituitary gland is decreased
     d. TSH produced by pituitary gland is increased
     e. It is often caused by Graves’ disease

Answer 149

d. TSH produced by pituitary gland is increased
- TSH stimulates thyroid gland to make thyroxin. If thyroxin in blood is high, then less TSH is released.

• Low TSH = hyperthyroidism
• thyroid gland uses iodine in food to make T4 (thyroxin) and T3 (triiodothyronine)

Question 150

435. Which procedure is most useful to study the intracellular location of proteins?
     a. Harshey-chase experiment
     b. Pulse-chase experiment
     c. Avery-MacLeod experiment
     d. NMR spectroscopy
     e. Electrophoresis

Answer 150

b. Pulse-chase experiment
- Pulse-chase involves using a radioactive label on a protein to detect what is happening to the molecules in cells. In this technique, one can track the fate of proteins through a cell, and learn important information about biochemical pathways.

Question 151

436. A reptile such as a lizard can tolerate drier terrestrial climates than an amphibian such as a salamander. Which of the following is not a trait possessed by a reptile to facilitate this tolerance?
     a. Thick shelled egg
     b. Internal fertilization
     c. Amniotic egg
     d. Loss of gills during development
     e. Thickened skin

Answer 151

d. Loss of gills during development
- Reptiles have thick skin, thick shelled eggs, an amnion, and internal fertiliztion. However, they do not lose gills at any stage of development.

Question 152

437. Which statement is false?
     a. Chemotrophs are organisms that use redox reactions to produce ATP
     b. Ubiquinone, also called Coenzyme Q, is a lipid-soluble electron carrier seen in the electron transport chain
     c. Eukaryotes and prokaryotes both utilize electron transport chains
     d. In oxidative phosphorylation, electrons are transferred from NADH to O2 through an electron transport chain to produce ATP
     e. Bacteria utilize a single electron transport chain to produce ATP

Answer 152

e. Bacteria utilize a single electron transport chain to produce ATP
- Bacteria use multiple electron transport chains, sometimes at the same time. Similar to eukaryotes, their electron transport chains involve proton pumps.

Question 153

438. Which statement is false?
     a. In a typical eukaryotic cell, the ph is usually around 7.4
     b. Amino acids are amphoteric; they can act as acids or bases
     c. The ph of gastric juice is under 2.0
     d. Glycine is the only optically active amino acid
     e. Hemoglobin and myoglobin are water soluble globular proteins

Answer 153

d. Glycine is the only optically active amino acid (false)

- Glycine is the only optically inactive amino acid since it has no chiral carbons.

Question 154

439. Which is unique to a mammal?
     a. backbone
     b. warm-blooded
     c. diaphragm
     d. 2 bones contained in middle ear
     e. all are true

Answer 154

c. diaphragm

• Fish and frogs are not mammals, but do have a backbone.
• Birds are not mammals but are warm-blooded.
• Mammals contain hair, produce milk to nurse their young, and have a lower jaw that is a single bone.
• 3 bones in middle ear are unique to mammals
• diaphrahm muscle is unique to mammals and is the major muscle of inspiration. The diaphragm separates the thoracic cavity from the abdominal cavity.

Question 155

441. After ovulation the ovarian follicle creates:
     a. corpus luteum
     b. primary oocyte
     c. secondary oocyte
     d. endometrial lining
     e. polary body

Answer 155

a. corpus luteum
- After ovulation has occured, the ovarian follice becomes the corpus luteum. The corpus luteum will produce progesterone and estrogen that will help blood vessel growth.

Question 156

442. Which of the following is derived from cholesterol?
     a. Cortisone and cotisol
     b. Progesterone and estroen
     c. Epinephrine and thyroxin
     d. A and B
     e. All of the above

Answer 156

d. A and B
- Cholesterol is the precursor to steroid hormones such as estrogens, progesterone, cortisone, cortisol, testosterone, and aldosterone. Epinephrine and thyroxin are amino acid derived.

Question 157

443. Which is true about ferns?
     a. they are vascular plants with large, feathery leaves
     b. they have large leaves with many veins
     c. Fern spores develop on the sporophyte in sporangia
     d. Sori, or clusters of sporangia develop on the lower surface of the leaf
     e. all are correct

Answer 157

e. all are correct
- In ferns, the predominant plant form is the sporophyte. Sporangia are structures in which spores are produced; clusters of sporangia are known as sori and are found on the lower surface of the leaf.

Question 158

445. Which statement is false?
     a. small uncharged polar molecules and lipids can readily move through a selectively permeable membrane
     b. fungi contain the polymer chitin
     c. Most digestion occurs in the small intestine
     d. The developing embryo will most likely attach to the endometrium
     e. Mitosis makes up 40 % of the cell cycle

Answer 158

e. Mitosis makes up 40 % of the cell cycle (false)

- Mitosis makes up about 10 % of cell cycle.

Question 159

448. An organism belonging to a………species will be distinctly male or female.
     a. monoecious
     b. dioecious
     c. gynoecious
     d. androecious
     e. hermaphroditic

Answer 159

b. dioecious
- Dioecious species cannot self-fertilize; they are a species in which each individual is distinctly male or female. Mammals and most reptiles are Dioecious. However, the term is used mainly for plant species.

Question 160

449. Which statement is false?
     a. The greatest specie diversity is seen in the tropical forest
     b. carbon dioxide is the major form of carbon in the atmosphere
     c. Secondary succession will occur to an area that once had life, such as in the case of a forest fire
     d. Humans illustrate an R-selected population
     e. Bacteria illustrate an R-selected population

Answer 160

d. Humans illustrate an R-selected population (false)

• K-selected population is one in which the members have low reproductive rates and are roughly constant in size. ex. humans
• R-selected population, such as bacteria, we see RAPID growth, numerous offspring, fast maturation, and very little postanal care is needed.

**Humans are OKAY (k-selected) species

Question 161

450. A study revealed that the haploid stage of a life cycle dominated. Which of the following organisms most likely is being depicted:
     a. frog
     b. fern
     c. fungi
     d. angiosperm
     e. man

Answer 161

c. fungi

Question 162

451. Which statement is false?
     a. Agonistic behavior can result if two animals conflict over a mate or food source
     b. xylem will transport water and minerals from the soil throughout a plant
     c. The casparian strip is a waxy band in plants that aid in water control
     d. The main solute transported by the phloem is sucrose
     e. None of these. All are true.

Answer 162

e. None of these. All are true.

Question 163

453. Which statement is false?
     a. Glycogen is a branched polymer of glucose
     b. Glycogen represents a stored energy called “potential energy” and is found in skeletal muscle and the liver
     c. Starch and glycogen are polymers of alpha glucose
     d. Glycogen can be stored intracellularly
     e. A greater number of polypeptides can be made with 20 different amino acids than polysaccharides

Answer 163

e. A greater number of polypeptides can be made with 20 different amino acids than polysaccharides (false)
- greater variety with polysaccharides. Polysaccharides can be branched or linear, whereas peptides are linear. Polysaccharides can be alpha or beta, whereas peptides cannot.

Question 164

454. Which statement is false?
     a. The B-pleated sheet represents a secondary structure held together by H bonds
     b. The alpha helix is held together by H bonds
     c. Myoglobin contains a quaternary structure
     d. Hemoglobin contains a quaternary structure
     e. All are true

Answer 164

c. Myoglobin contains a quaternary structure (false)

• Quaternary structures is for proteins with more than one polypeptide chains. Hemoglobin has 4 polypeptides (2a and 2b), myoglobin has only one.
• Alpha helix and beta sheets are secondary structures held together by H bonds.

Question 165

456. In the glomerular filtrate, which of the following should be completely reabsorbed?
     a. K+
     b. Na+
     c. Urea
     d. Glucose
     e. Bicarbonate ion

Answer 165

d. Glucose
- Usually, all the glucose in glomerular filtrate is reabsorbed. This reabsorbtion occurs in the proximal convoluted tubule. However, in diabetes, blood glucose levels rise high, and significant quantities of glucose appear in the urine.

Question 166

458. Which statement is false?
     a. Action potentials cause the release of neurotransmitters into the synapse
     b. At rest [K+] inside > [K+] outside
     c. Few Na+ ions enter a cell under resting conditions
     d. A neurotransmitter is removed from the synapse either by enzyme degradation, re-uptake or simple diffusion
     e. Nerve gases are potent inhibitors of glycolytic enzymes

Answer 166

e. Nerve gases are potent inhibitors of glycolytic enzymes (false)
- Nerve gases are potent inhibitors of acetylcholinesterase, and cause death by respiratory paralysis.

Question 167

459. Which of the following is NOT true of Tay-Sachs disease?
     a. A critical lysosomal enzyme is absent
     b. Brain cells develop a lipid buildup
     c. It is an autosomal recessive disorder
     d. The disease is usually non-fatal
     e. All of the above are true

Answer 167

d. The disease is usually non-fatal (false)
- Tay-sachs disease is an autosomal recessive disease in which a lysosomal defect occurs and causes lipid buildup in brain cells. The disease is fatal in the first five years of human life. During the disease, mental retardation, blindness, and eventually death occur.

Question 168

460. Which of the following are false?
     a. Blood pressure = cardiac output x peripheral vascular resistance
     b. As the radius of a blood vessel decreases, velocity and blood presure increase
     c. As cardiac output increases, blood pressure increases
     d. Increasing stroke volume increases blood pressure
     e. Blood pressure is indirectly related to cardiac output

Answer 168

e. Blood pressure is indirectly related to cardiac output (false)

• Blood travels fastest at a constriction. Radius of blood vessel is most important factor that affects blood flow (BP is inversely related to Radius^4)
• Peripheral vascular resistance refers to friction between blood and walls of blood vessel.
• BP = CO x PVR
• CO = stroke volume x heart rate

Question 169

462. What is true about smoth muscle?
     a. It is found in aorta, pulmonary artery, esophagus, and bladder
     b. It is mononucleated
     c. Involuntary muscle that is slow to contract
     d. They respond to stimulation with action potentials
     e. All are correct

Answer 169

e. All are correct

Question 170

463. The food and air passages cross where?
     a. Pharynx
     b. Larynx
     c. Bronchi
     d. Alveoli
     e. Nasal cavity

Answer 170

a. Pharynx
- Air and food passages cross in pharynx region. Gas exchange will occur in alveoli by passive diffusion.

**Pharynx is a ferri

Question 171

464. Which is correct about hydrogen peroxide?
     a. the formula is H2O2
     b. Ctalase can convert H2O2 to H2O and O2 since it is toxic to cells
     c. It can be an oxidant (oxidizing agent) such as that found in toothpaste
     d. Peroxisomes are membranous vesicles that contain enzymes to break down H2O2
     e. All are true.

Answer 171

e. All are true.

Question 172

465. Which analytical technique is incorrectly matched?
     a. Western blot: Detects specific proteins in tissues
     b. Southern blot: Detects DNA sequences in DNA samples
     c. Northern blot: Detects RNA in a sample
     d. Fluorescence correlation spectroscopy: Studies cell-to-cell communication
     e. All are correctly matched.

Answer 172

e. All are correctly matched.

• SNOW DROP
• Southern = DNA
• Northern = RNA
• Western = Protein

Question 173

466. Which buffer system works primarily in the intracellular fluids?
     a. Nitrate buffer
     b. Calcium carbonate buffer
     c. Phosphate buffer
     d. Hemoglobin buffer
     e. Amino acid buffer

Answer 173

c. Phosphate buffer

• Intracellular fluids: Phosphate buffer. H2PO4(-) and HPO4(–) act as the acid and base respectively. Phosphate is abundant in cells and will act as the major intracellular buffer.
• Extracellular fluid: Bicarbonate buffer, HCO3(-)/H2CO3 system

Question 174

467. Which is the correct sequence of inspired air?
     a. Nasal cavity, trachea, bronchus, bronchiole, alveoli
     b. naval cavity, trachea, bronchiole, alveoli, bronchus
     c. Nasal cavity, trachea, brochiole, bronchus, alveoli
     d. Nasal cavity, lung, bronchus, alveoli
     e. Nasal cavity, trachea, bronchiole, pharynx, alveoli

Answer 174

a. Nasal cavity, trachea, bronchus, bronchiole, alveoli

Question 175

468. Which of the following contains a contractile vacuole?
     a. Paramecium
     b. Amoeba
     c. Hydra
     d. Sponges (fresh water)
     e. All of the above

Answer 175

e. All of the above
- Protozoans and sponges have contractile vacuoles. This organelle collects water from various parts of the cell and pumps it out by rhythmic contractions.

Question 176

469. Which statement is false?
     a. the main function of large intestine is resorption of water, sodium, and other minerals
     b. Large intestine harbors bacteria which are the main source of vitamin K production
     c. Bulk of feces consists of bacteria, cellulose fibers and other indigestible substances
     d. Glucose and other sugars are absorbed into the blood from intestinal tract and reach liver via portal vein
     e. All statements are true

Answer 176

e. All statements are true

• The main function of the large intestine (colon) is resorption of water, sodium, and other minerals. The bacteria in the large intestine produce vitamin K. These bacteria are the chief source vitamin K. Feces are stored briefly in rectum and eliminated through the anus.
• The portal vein directs glucose and other monosaccharides to the liver. Thus, the large intestine functions in not only as waste storage, but also water conservation and ion regulation.

Question 177

471. A certain autosomal recessive condition is seen in approximately 1 in every 50 people, but is symptom-free. If a male and female carry the gene, what is the probability that they have a diseased child?
     a. 5 %
     b. 1 %
     c. 0.1 %
     d. 0.01 %
     e. 10 %

Answer 177

d. 0.01 %

• Each parent has 1/50 (2 %) chance of carrying the gene. And there is 25% is the probability of having an autosomal recessive disorder.
• Answer: (.02)(.02)(.25) = 0.0001 = .01 %

Question 178

472. A sperm cell is unable to fertilize oocytes upon immediate ejaculation, which process must occur first?
     a. Apoptosis
     b. Capacitation
     c. Dysplasia
     d. Implantation
     e. Polarization

Answer 178

b. Capacitation
- Capacitation is requried by spermatozoa in the female oviduct and uterus that allows for egg penetration. Capacitation is a functional maturation of the spermatozo. During capacitation process, physiological changes occur in the spermatozoa. These changes include changes in sperm intracellular ion concentrations, motility, and metabolism

Question 179

473. Which statement is correct:
     a. Malphighian tubules are the excretory organ of insects
     b. Aquatic animals such as bony fish excrete ammonia because it is easily eliminated in water
     c. Birds, insects, and reptiles excrete uric acid
     d. Cells of the proximal convoluted tubule have a huge abundance of mitochondria
     e. All are correct

Answer 179

e. All are correct

• Cells of proximal and distal convoluted tubule are very rich in mitochondria. The proximal convolutd tubule in particular carries out much of the active reabsorption. Mitochondria supply energy for active transport.
• Ammonia is waste product of aquatic animals, while birds, reptiles, and insects excrete uric acid.
• insects such as the grasshopper contain malphighian tubules.

Question 180

474. Which protein is associated with a flagellum?
     a. Albumin
     b. Chymotrypsin
     c. Insulin
     d. Tyrosinase
     e. Dynein

Answer 180

e. Dynein

- Dynein may also be invovled in chromosomal movement.

Question 181

475. Which statement is false?
     a. Flagella and cilia have a 9+2 arrangement of microtubules
     b. Dynein “arms” are attached to the microtubules and serve as molecular motors
     c. Cytoskeleton is contained within the cytosol
     d. Microfilaments, microtubules an intermediate filaments are the primary types of fibers comprising cytoskeleton
     e. Cytoskeleton is found only in eukaryotic cells, and gives shape to a cell and aids in cellular movement

Answer 181

e. Cytoskeleton is found only in eukaryotic cells, and gives shape to a cell and aids in cellular movement (false)
- Prokaryotes and eukaryotes contain a cytoskeleton.

• Microfilaments: actin
• Intermediate filaments: keratin
• Microtubules: tubulin

Question 182

478. Which statement is false?
     a. a lymphatic vessel is most similar to that of an artery
     b. The thymus of a 35 year old is most likely smaller than that of a 2 year old
     c. Lysozyme is an enzyme found in body fluids such as tears which aid in destroying certain bacteria
     d. The coating of a microbe with antibodies to make it more susceptible to phagocytosis is called opsonization
     e. As an individual ages, the cytotoxic T-cells are greatly affected

Answer 182

a. a lymphatic vessel is most similar to that of an artery
(false)

• A lymphatic vessel is most similar to a vein; they have internal valves.
• Thymus makes thymosin which stimulatees T-cell development. Once puberty is reached, the thymus gland shrinks and is replaced by fat.
• Lysozyme is an enzyme found in tears and saliva.
• Functional capacity of T-cells is most influenced by aging. After age 60, declines in the immune system are most evident.

Question 183

480. Acid hydrolases are contained in which cellular organelle?
     a. Ribosome
     b. Smooth endoplasmic reticulum
     c. Lysosome
     d. Nucleolus
     e. Golgi complex

Answer 183

c. Lysosome

• Acid hydrolases are contained in the lysosome. The interior of this membrane-bound organelle has a pH of 5, and contains enzymes that hydrolyze proteins, lipids, nucleic acids, and carbohydrates.
• Lysosomes are also called the “suicide bags” of the cell. Cells that are not needed anymore are destroyed in these bags or sacs.

Question 184

482.

Answer 184

Myogloin vs. hemoglobin

Question 185

483. Which statement about the skin is true?
     a. the epidermis has no blood supply
     b. The stratum corneum is the surface layer which varies considerably in thickness
     c. the stratum granulosum is that layer containing granules which can easily stain
     d. The stratum germinativum contains dividing cells
     e. all are true

Answer 185

e. all are true
- the skin is made up of the outermost epidermis, followed by the dermis, consisting mostly of connective tissue, hair follicles, sesnsory receptors, erector muscles, sweat, and sebaceous glands. Below the dermis is fatty tissue that serves asa cushion and an insulator. The epidermis has no blood supply, and depends on teh dermis for oxygen and nutrients. Several layers of skin make up the epidermis: stratum germinativum, spinosum, granulosum, lucidum, and corneum.

Question 186

484. Which statement is false?
     a. blood travels slowest in capillaries and has the lowest average blood pressure in veins
     b. CO2 reacts with water and the following equilibrium is seen: CO2 + H2O H2CO3 HCO3- + H+
     c. Oxygenated blood from the pulmonary veins goes into the left atria of the heart
     d. The opening of heart valves causes the lub and dup sounds associated with the heart
     e. In the hear of an amphibian such as a frog, two atria and one ventricle are generally noted

Answer 186

d. The opening of heart valves causes the lub and dup sounds associated with the heart (false)
- closing of the valves causes the lub dub sounds. Lub is closing of AV valves. Dup is closing of semilunar valves.

Question 187

486. Which statement is false?
     a. Determinate cleavage is a characteristic of protostomes
     b. Protostomes include mollusks, annelids, and arthropods
     c. In protostomes, the blastopore eventully develop into the mouth, while in deuterostomes the blastopore eventually develops into the anus
     d. A mollusk will show determinate cleavage
     e. All statements are true

Answer 187

e. All statements are true

Question 188

487. Consider the oxygen-hemoglobin dissocation curve below. If the pH was decreased how would this change the curve?
     a. The curve will change from hyperbolic to sigmoidal
     b. The curve will shift to the left
     c. The curve will not cahnge since hemoglobin is an allosteric molecule
     d. The curve will shift to the right
     e. The curve will become linear

Answer 188

d. The curve will shift to the right
- If the pH was decreased, or the temperature was increased, more oxygen would be given up. An increase in CO2 also shifts the curve to the right. If the curve is shifted to the right, it simply means more oxygen is unloaded by hemoglobin.

Question 189

488. A patient gets a vaccination from his doctor. Which of the following type of immunity would result?
     a. passive immunity that is naturally acquired
     b. Passive immunity that is artifically acquired
     c. Active immunity that is naturally acquired
     d. Active immunity that is artificially acquired
     e. None of these

Answer 189

d. Active immunity that is artificially acquired
- Vaccination is an immunization against a given pathogen; it is artificially acquired. Production of immunological agents begins. This process is active immunity that is artificially acquired.
- If you ever recovered from chicken pox, immunity was conferred by active immunity that was naturally acquired.
- antibodies may be transferred from one individual to another providing passive immunity. i.e. a preganant mother transfers antibodies across placenta (naturally acquired)

Question 190

489. Consider the fluid mosaic model for cell membranes. Which is false?
     a. Membrane proteins are embedded in the lipid bilayer
     b. The bilayer is symmetric
     c. Both proteins and lipids are free to move laterally in the plane of the bilayer
     d. Movement of proteins and lipids is restricted if movement occurs from one face of the bilayer to the other
     e. Carbohydrate moieties attached to either lipids or proteins are exposed to extracellular face of the membrane

Answer 190

b. The bilayer is symmetric
- inside not same as outside.
- Proteins and lipids are capable of lateral movement but movement of either from one face to the other is prohibited.

Question 191

494. Consider the following diagram of two cells. A cell-surface component is specifically labeled with a fluorescent chromophore “tag”. The fluorescene was monitored and showed that both cells became fluorescen after a time period. Which of the below structures allowed for the “communication”?
     a. Cell nucleus
     b. Gap junction
     c. Desmosome
     d. Centrosome
     e. Tight junction

Answer 191

b. Gap junction
- Tight junctions seal spaces between cells –>intestinal cells. Gap junction will allow cells to exchange nutrients and for “molecular communication”

Question 192

496. Which of the following is false about Down syndrome?
     a. It may originate through nondisjunction of chromosome 21
     b. Failure of paired homologues to disjoin during Anaphase I or II could result in Down syndrome
     c. It is an autosomal disorder which occurs equally in both sexes
     d. A and C
     e. All of the above are true

Answer 192

e. All of the above are true

Question 193

497. Which of these are true about keratin?
     a. Keratins are a family of fibrous proteins
     b. Keratin is found in mammals, reptiles, bird and amphibians
     c. Claws, horns, hooves, and nails of animals contain keratin
     d. The epidermis is almost waterproof because of its keratin matrix
     e. All are correct

Answer 193

e. All are correct

- keratin can be soft (feather) or very hard (turtles) due to disulfide bridges.

Question 194

500. Which statement is false?
     a. The optic disc is also called the “blind spot”
     b. The optic disc contains no photoreceptors
     c. The optic disc represents the optically insensitive area in the retina where fibers of the optic nerve emerge from the eyeball
     d. The ciliary muscle of the eye can change the shape of the lens of they eye
     e. When focusing on a nearby object the ciliary muscle relaxes and flattens out

Answer 194

e. When focusing on a nearby object the ciliary muscle relaxes and flattens out (fasle)
- If the ciliary muscle relaxes, the lens flattens and this allows the lens to focus on a distant object.

Question 195

501. Which statement is true regarding progesterone?
     a. Progesterone is a steroid hormone which is likely to assist sperm motility
     b. Cholesterol is a precursor to progesterone
     c. Progesterone inhibits lactation during pregnancy
     d. The fall in progesterone levels following delivery is one of the factors allowing milk production
     e. All statements are true

Answer 195

e. All statements are true
- Progesterone is a steroid hormone found in both men and women and is derived from cholesterol. Studies have shown it might be involved in sperm motility. Progesterone inhibits lactation during pregnancy and allows for milk production after delivery.

Question 196

502. Arrange in correct chronological order fromoldest to most recent.
     a. Jawless fish, bony fish, reptiles, birds, amphibians, mammals
     b. Bony fish, jawless fish, birds, amphibians, reptiles, mammals
     c. Jawless fish, bony fish, amphibians, reptiles, birds, mammals
     d. Jawless fish, bony fish, reptiles, amphibians, birds, mammals
     e. Jawless fish, bony fish, amphibians, birds, reptiles, mammals

Answer 196

c. Jawless fish, bony fish, amphibians, reptiles, birds, mammals
- Ancestral vertebrates began with jawless fish

Question 197

503. An animal-like protist that uses pseudopodia to move and feed is;
     a. Amoeba
     b. Paramecium
     c. Bacterium
     d. Euglena
     e. Mushroom

Answer 197

a. Amoeba
- All protists are eukaryotic and most have flagells or cilia at some point in their life cycles. The euglena has a flagellum,, the paramecium has cilia, and the amoeba has pseudopodia.

Question 198

504. Which statement is true?
     a. Surfactant reduces surface tension and allows the fetus to breathe easier
     b. Surfactants are substances present in the alveoli of the lungs
     c. Without adequate quantities of surfactant, an infant would have difficult breathing
     d. A and C
     e. All are true.

Answer 198

e. All are true.
- First few breaths that a newborn infant takes are extremely labored. Alveoli contain substances called surfactants which reduce the surface tension of the fluid within the infant’s lungs. Once the alveoli are expanded, they tend to stay expanded and not collapse under surface tension after each breath. Therefore, collapsed lungs, surface tension, and small airways offer much resistance to air movement. Stimulation of first breath is initiated by high CO2 levels.

Question 199

505. Which statement is true?
     a. Eustachian tube is a narrow passage leading from pharynx to cavity of middle ear
     b. Respiratoey control centers are located in medulla and pons
     c. Tidal volume is air exchanged during normal breathing
     d. Negative pressure occurs during normal physiologic inspiration
     e. All are true

Answer 199

e. All are true
- During inspiration, the lung volume will increase, resulting in a decrease in lung pressure compared to the atmospheric pressure. (Boyle’s law). Increase in volume is brought about by contraction of the diaphragm.