exam answer keys Flashcards
although there are many kinds of specialized cell types, there are only ____ kinds of tissues.
4
the strength of skin and of the connections between bones is due to the protein ______.
collagen
which of the following statements about muscle tissue is false?
it is a form of connective tissue
which type of tissue is responsible for secreting digestive enzyme?
epithelial
which of the following is the correct pairing between the muscle type and feature?
cardiac- branched cells arranged in interlinked network
which of the following describes an involuntary control of muscle?
pupil constriction in response to light, and movement of gut to mass food through
which of the following muscle types uses calcium ions to trigger actin-myosin interactions for movement?
cardiac, smooth, and skeletal
the strength or weakness of a muscle contraction depends on the number of motor units activated and the frequency at which they are firing. An increase in either of these 2 factors allows for graded contraction through the process of ____.
summation
most of the water in the body is found ____.
intracellularly
suppose that the rate of a particular biological function at 15 degrees C is X. If the Q10 of that function at 25 degrees C is ____, the rate is ____.
1; X
environmental temperature influences the body temperature of many animals, especially those that live in ____ environments.
aquatic
predict the probable metabolic response of a mammal exposed to a 3-5 degree C environmental temperature change from 0 degrees C.
decreased metabolic rate
some organisms, such as grasshoppers, earthworms, and squids, have clusters of neurons called ____.
ganglia
when you read this question and your nervous system sends the information from your eyes to your brain, the information is carried by ______.
afferent neurons
what is the difference between glia and neurons?
glia are cells that nourish and support the neurons
which of the following brain areas integrates sensory and motor information?
cerebellum
the resting potential across the neuronal membrane is generally maintained by the _____.
sodium-potassium pump
most synapses ______.
in vertebrates are chemical synapses; cover a space about 25 nm wide; are crossed by neurotransmitters; are about 1/2000th the width of a human hair
directly following depolarization, the neural membrane potential is restored in some neurons when…
K+ ions rush outward through the membrane
in general, ____ are cells of the nervous system that transduce physical or chemical stimuli into signals that are transmitted to other parts of the nervous system for processing and interpretation.
sensory cells
chemoreceptors _______.
are possessed by all animals, including humans, and can cause strong behavioral responses
what is the physiological basis for the auditory system’s ability to distinguish different sound frequencies?
different sections of the basilar membrane respond differentially
the respiratory system of insects consists of _____.
branched air tubes called tracheae that supply capillaries
which of the following is not seen in fish gills?
bidirectional ventilation of the gills
the lungs expand in inhalation because _____.
the volume of the thoracic cavity increases
oxygen can be exchanged more easily in air than in water because ____.
the oxygen content of air is higher than that of water, oxygen diffuses more slowly in water than in air, and more energy is required to move water than air because water is denser
a cardiovascular system is not necessary in the hydra because the hydra _____.
is only 2 cells thick.
imagine that a paleontologist finds a fragment of a fossilized vertebrate that indicates that the animal had a 4-chambered heart. The animal could be a _______.
crocodile or bird
which of the following is an example of an animal with an open circulatory system?
grasshopper
as blood enters the capillaries from the arterioles, blood pressure _____ and surface area _____.
decreases; increases
primates should eat citrus fruits to prevent scurvy, which is due to a deficiency of _____.
ascorbic acid
organisms that derive their energy and molecular nutrients from other organisms are called _____.
heterotrophs
a mammal with a diet of grain and leaves would be expected to have which kind of teeth?
prominent molars and small canines
what hormone induces loss of chlorophyll, causing leaves on trees to appear red, yellow, or orange, then abscise (fall off) in autumn?
ethylene
what hormone is responsible for stems bending toward light?
auxin
if green bananas are placed in a closed bag they will ripen much more quickly compared to green bananas left in the open. This hastened ripening is caused by which hormone?
ethylene
when plants are in very dry soil, they can fight off death by desiccation by closing their stomata. Which hormone is deployed to override the stomate-opening stimuli?
abscisic acid
stem elongation, fruit enlargement, and seed germination are all stimulated by which hormone?
gibberellic acid
which of the following is not part of the mechanism by which a hormone causes changes in gene expression?
the hormone stimulates the synthesis of its receptor protein in a target cell
which of the following is not part of the process of phototropism?
low levels of auxin on the shaded side causes increased growth on that side, resulting in bending
which of the following statements about petals is not true?
they are the only kind of organ found in flowers
meiosis takes place in flowers. which of the following best describes where?
in ovules inside the ovary and in the anther of stamens
which of the following statements is not true of pollen in angiosperms?
sperm in pollen move by posterior flagella
which of the following is not a mechanism that increases the likelihood that seeds contain embryos with 2 different parents?
hermaphroditic flowers
angiosperms exhibit double fertilization. which of the following best describes what develops from this process?
embryo and endosperm
which of the following hormones directly stimulates molting in an insect larva?
ecdysone
steroid hormones _____.
must bind to carrier/transport proteins to be transported in the blood to their target cells
malfunctioning of the thyroid gland in the human adult can result in ______.
goiter
which hormone is responsible for the conversion of glycogen into glucose when serum levels fall?
glucagon
which of the following is the correct order of movement down the axis?
hypothalamus –> posterior pituitary –> kidney
when a hormone’s receptor is on the cell that secretes the hormone, the cell is said to have an ______ function.
autocrine
which of the following statements about sex steroids is false?
absence of the X chromosome causes the embryonic gonads of mammals to produce androgens
defensins, which are toxic to a wide range of pathogens, are produced by _____.
mucous membranes
which of the following cells release histamines upon damage?
mast cells & basophils
which of the following statements about natural killer cells are false?
they release cytokines
which of the following must take place for a B cell to become an antibody-secreting plasma cell?
binding to the antigen by a helper T cell that has the same specificity as the B cell
B lymphocytes specific for certain antigens proliferate by a process known as…
clonal selection
One V gene, one D gene, and one J gene encode for the _____ region of the _____ chain of a specific antibody.
variable; heavy
which of the following statements about AIDS is false?
AIDS stands for “autoimmune deficiency syndrome
which of the following statements is false about MHC proteins?
class II MHC proteins are the only class found on the surfaces of T cells
also known as antigenic determinants, _____ are specific sites on the antigen that are recognized by the immune system.
epitopes
which of the following statements is true?
memory B cells can persist in the body for several decades
animal reproduction without sex ______.
occurs by budding, parthenogenesis, regeneration, and is mostly seen in invertebrates
parthenogenesis, or the development of offspring from unfertilized eggs, _______.
depends on cyclical hormone states in whiptail lizards, and allows some species to produce only females
semen, which is the fluid matrix for sperm during emission and ejaculation, contains all of the following except ______.
glucose to serve as an energy source for the sperm
in the early half of the menstrual cycle, before ovulation, the steroid hormone at its highest level in the blood is ______.
estrogen
which of the following indicates a human is about to ovulate?
egg white-like cervical fluid, and a soft, high cervical position
which birth control method prevents ovulation?
birth control pill
which of the following anatomical features is shared in most mammals by both the reproductive and excretory systems?
urethra
which of the following statements about the grey crescent in amphibian zygotes is incorrect?
it forms at the site of sperm entry
which of the following is not true of processes that occur during cleavage?
cell divisions occur by meiosis
after gastrulation, the ectoderm cells give rise to the developing _____.
skin
when a 2-celled snail embryo was treated so that the 2 cells were separated from each other and kept alive, they each developed into half a snail larva. this is an example of _____ development in which _____ were likely important for normal development.
mosaic; cytoplasmic determinants
polydactyly in cats is fairly common. the extra digits in the paws are the result of ______.
a second site of Shh production, on the anterior side of the limb bud
nuclear transplantation experiments in a mammal were successful first in a sheep. what was the significance of this result?
it demonstrated that somatic cells were not irreversibly differentiated and retained the capacity for totipotency
amphibians split their lives between aquatic and terrestrial environments, and this is reflected in the body form, which changes dramatically during metamorphosis. which of the following is not correctly paired with developmental state?
gills for respiration- adult
if a piece of ectoderm destined to be the outer layer of skin is moved from one early gastrula to a location destined to become neural tissue in another early gastrula, which of the following will result?
the transplanted tissue will develop into neural tissue
an annelid moves by _______.
alternating contractions of longitudinal and circular muscles
which of the following statements about endoskeletons of vertebrates is false?
the rib bones are part of the appendicular skeleton
the role of cartilage in the skeleton is to ______.
add flexibility
cells that break down or resorb bone are the ______.
osteoclasts
to osmoregulate in fresh water, a fish must ______ salts and produce ______ amounts of ______ urine.
conserve; copious; dilute
the functional unit of the kidney is ______.
a nephron
the human body’s response to dehydration is to __________.
release ADH from the posterior pituitary, rise in blood osmolarity, increased permeability of the collecting ducts in the kidney, and increased Na2+ reabsorption stimulated by aldosterone
which of the following is most toxic to cells?
ammonia
the young goslings that followed Konrad Lorenz around as if he were the parent goose were exhibiting ______.
imprinting
upon returning to the hive, honeybee foragers perform the ______ dance to signal the distance and direction of a distant (more than about 100 km away) food source.
waggle
the ultimate cause of a behavior are those that have shaped the behavior’s ______.
evolution
what do proximate explanations of behavior focus on?
genetic, neurological, and hormonal mechanisms of behavior
which of the following is the earliest event in puberty?
the hypothalamus releases more GnRH
in angiosperms, which of the following cell types is incapable of entering the cell cycle to undergo mitosis?
egg
which of the following best describes the genetic relatedness of components of a eukaryotic cell?
nuclear DNA closest to archaea DNA, chloroplast DNA closest to cyanobacteria DNA
which of the following is an example of cell division after which one daughter cell forms a secondary wall but its sister does not?
cell division in the vascular cambium to produce a tracheid
which of the following do viruses not require in order to spread?
use of the host cell’s spindle apparatus
if you have 2 samples of bacterial colonies that you subject to Gram staining, which of the following conclusions would be valid?
if they both stain purple, they are likely to be related & if they both stain purple, then it is impossible to draw a conclusion about relatedness
the first molecular phylogenies were constructed by comparing the sequence of rRNA from different organisms. which of the following was not part of the choice to use that starting material?
rRNA molecules are extremely long and thus provide a great deal of sequence for comparison
which type of horizontal gene transfer involves a living DNA donor?
conjugation
cholera is a disease caused by the bacterium Vibrio cholerae, which spreads through contaminated water. it causes severe diarrhea and dehydration, and can be fatal in as little as a few hours if left untreated. cholera produces an exotoxin, which :
is a protein produced by living Vibrio and secreted into the host (intestine)
HIV is an RNA retrovirus which causes the disease AIDS in humans. which of the following enzymes must its genome encode in order for it to spread?
reverse transcriptase
all eukaryotes exhibit sexual reproduction but life cycles in different groups vary. which of the following best describes that variability?
all eukaryotes undergo fusion, meiosis, and mitosis, but mitosis occurs only after fusion in animals and some protists
which of the following superkingdoms feature protists that move and eat using their cytoskeleton to shift their cytoplasm from one side of the cell to the other?
amoebozoans and rhizarians
this summer Iowa saw two deaths from infections by a so-called brain-eating amoebas. the protist responsible for the infection is actually a member of the Excavates. Excavates are as closely related to amoebas ass corn plants are to:
diatoms
examples of green algae include those that are single cells, like Chlamydomonas (left), colonial, like Gonium (middle), and multicellular, like Volvox (right). the differences among them are the result of all except which of the following?
colonial species are special because they reproduce asexually and thus never undergo meiosis
Euglenids, in the Excavates superkingdom, have chloroplasts that are derived from the endosymbiosis of a green alga. evidence of this comes from the number of membranes surrounding the Euglena chloroplast. ordering these membranes from the inside out, they originate from:
a cyanobacterium, the vesicle of the ancestor of the green algae, the cell membrane of the green algae symbiont, and the vesicle of the ancestor of the Euglenid
virus classification is based on:
what kind of nucleic acid comprises their genomes
fungi and animals are in the same superkingdom. which of the following traits is incorrectly assigned to these 2 clades?
cell walls in both
which of the following does/did not have an amniotic egg?
frog
which of the following statements is not true of axillary buds in shoots?
they originate from the pericycle, a layer of cells just outside the vascular tissue
although multicellularity in the ancestors of the flowering plants (angiosperms) and triploblastic (having 3 body layers) animals evolved independently, phylogenies based on genome sequences revealed that the feature that distinguishes the primary subdivision within both of those 2 groups is:
embryo organization
unlike animals whose diversification of form occurred both in aquatic and terrestrial environments, the diversification of plants was driven largely by selection of traits that allowed them to succeed in terrestrial/aerial environments. which of the following lists the traits in order they evolved?
vascular tissue, leaves, seeds, flowers
mosses, liverworts, and hornworts are often described collectively as nonvascular plants as they lack differentiated cell types specialized for transport of fluids. they also differ from other land plants in having:
a dominant gametophyte generation
in Shakespeare’s Henry IV, a character says, “we have… fern-seed; we walk invisible.” this line reflects botanical knowledge at that time, when plants were known to come from seeds but no one had ever found the seeds of ferns (thus, they must be invisible, and furthermore, if you carried one you’d be invisible too!). we now know that when ferns reproduce sexually, they disperse their offspring by shedding:
spores
a photosynthetic, multicellular eukaryote having 2 unequal flagella is most likely a member of:
stramenopiles
arthropods as a group display metamerism, a body comprised of similar segments that can become specialized to perform different functions. choose among the following the list that ranks arthropods with least to most specialization among segments:
myriapods, crustaceans, chelicerates, hexapods
which of the following is not true of bud scales on tree branches?
they are very small during the winter but once spring arrives, they grow, green up, and conduct photosynthesis
which of the following incorrectly identifies the location where meiosis occurs in these land plants?
moss- in the antheridium and archegonium (where sperm and eggs are produced)
which of the following groups of animals lack cephalization (a head where sensory organs are clustered near the mouth)?
cnidarians
when water is taken up by a root hair, where does it go next?
it either enters the cytoplasm of a cortical cell, or it is drawn to the cell wall of an endodermal cell
the enzyme cellulase can be used to remove the cell wall from cells in small samples of leaf tissue without damaging the contents of the cells, which stay alive. if a so-called protoplast, with a water potential of -0.7 was placed in a solution with a water potential of -0.6, at equilibrium:
the protoplast would burst
stomata opening size can be regulated by the plant in order to optimize photosynthesis and minimize water loss when photosynthesis cannot take place. which of the following are not part of the mechanism that allows the guard cells to change shape to regulate the opening size?
a constant concentration of potassium ions in the guard cell vacuole
transpiration pull is the name for the mechanism that allows water to move efficiently through tracheids and vessels. which of the following is not part of this process?
roots pump water in from the soil
the dry weight of a plant is closest to what percent carbon?
40%
legumes have been important in crop rotation plans because of their ability to enrich the soil even when they are also providing produce whose harvest has the effect of removing soil nutrients. which of the following is not part of the mechanism by which legumes provide this service?
rhizobium bacteria continuously produce NOD factor to cause legume seeds to germinate
which of the following plant mineral nutrients is considered a micronutrient?
boron
in order for sugars made in leaves to be distributed to other, non-photosynthetic organs and tissues, they are loaded into the phloem as a solution. which of the following best describes the force that drives their distribution?
high solute concentrations at the point of phloem loading draw water from adjacent tissues to set up high hydrostatic pressure which pushes the phloem sap out throughout the plant
when fully differentiated, none of these cell types can synthesize new proteins except:
pericycle cells
plants exhibit indeterminate growth, thanks to the action of clusters of “stem cells” located at the tips of the shoot and root. the special nature of these meristem cells is that
they never differentiate so that they can continue to divide
which of the following does not stimulate stomatal opening?
wilting
in order to transport K+ ions into their cells, plants
pump H+ out
which of the following is not a sink with regard to movement of sap in the phloem?
the mesophyll of a leaf of a banana tree
active transport of sucrose into sieve elements
allows very high levels of sucrose to build up, which draws in water from adjacent cells and establishes the force that propels sugars away from source organs
in a typical eudicot leaf, most of the chloroplasts are found in the
palisade mesophyll cells
which of the following is the best diagnostic feature that would allow you to determine whether a cylindrical portion of a plant was stem and not root?
presence of axillary buds
which of the following statements about secondary growth is incorrect?
differentiating daughter cells closer to the center of the stem are likely to become a sieve element
for optimal growth, plants must obtain essential elements from their environment. which of the following is not an adaptation by some plant that ensures that it has an adequate supply of all the elements it requires?
hydroponics
