IB BIO FALL FINAL

Question 1

explain apical growth in plant shoots

Answer 1

-primary source of growth for plants
-occurs in the shoots and roots
-lengthening of the plant grow taller so it can gain more water and co2
-Develops into primary xylem and phloem
-leaf development
-growth is due to cell elongation and mitosis,
-shoot apical meristem= cells are actively carrying out mitosis & cell division for elongatation
-when one meristem cell divides: one cell becomes differentiated (used for a specific part of the plant) while the other one stays a meristem for more growth (ensuring totipotent cell growth)
-new differentiated cells go to the edge of the apcial meristem and stop divided to become stem and leaves
-leaves are initiated as small bumps on the side of the apical dome (called leaf primordia)
-as the stem continues to grow from the apcial meristem, some meritstem cell remain called the “axillary” bud

Question 2

explain the process of phototropism in plants

Answer 2

-plants grow toward the light (positive tropism)
-plants grow toward the ground (negative tropism)
-controlled by auxin:
-auxin promotes growth by lengthening plants and altering gene expression (auxin is spread evenly through the plants)
-auxin efflux pumps actively transport auxin out of the cells to redistribute

Question 3

Discuss (pros and cons) the use of micropropagation to reproduce plants.

Answer 3

-asexually reproduce large numbers of identical plants in glass
-micropropagation is highly effective but expensive
-rapid bulking
-production of virus-free strains
-propagation/reproduction of endangered species

Question 4

Draw and Label a half-view of an animal pollinated flower (w/functions)

Question 5

Outline the relationship between flowers and pollinators

Answer 5

-mutualistic relationship
-both benefit
-animal gets nectar
-plants get pollinated
-species coevolved with pollinators species

Question 6

Distinguish between pollination and fertilization in flowering plants

Answer 6

-pollination: physical transfer of pollen from the anther to the stigma of a flower
-fertilization: the fusion of haploid nuclei (male pollen grain fuses with the female ovule to produce a diploid zygote)

Question 7

Describe the conditions needed for seed germination

Answer 7

-favorable conditions for the seed to begin sprouting
-water for rehydration
-oxygen for aerobic respiration
-pH (enzyme function)
-ideal temperature (enzyme function)
-SOME SEEDS: fire, freezing, digestion, washing,
-STEPS:
-water is absorbed to trigger the synthesis of gibberellin
-GA (gibberellin acid) plant growth hormone turns genes that synthesize amylase
- amylase hydrolyzes starch into maltose
-maltose is hydrolyzed into glucose
-seed it now metabolically active, seed coat ruptures and radicle grows into the ground
-cotyledon emerges

Question 8

Explain the process of photoperiodism in long-day and short-day flowering plants (phytochrome)

Answer 8

-flowering in some plants is controlled light, a plant’s response lengths of night
-length of darkness
-long-day plants: flower during the day because the nights are shorter (summer)
-short-day plants: flower when days are short and nights are long (winter)
-phytochrome: blue-green pigment, that
absorbs wavelengths of light
-flowering involved gene expression: two different forms
-Pr (inactive form) absorbs red light to convert into Pfr
-Pfr (active form) absorbs FAR light rapidly converting back into Pr
-Pfr made int he day converts back to Pr form in the dark (less energy to maintain) but very slowly
-length of night determines how much pfr will remain
-pfr remaining after the night, promotes flowering by activating specific genes in the shoot apex
-

Question 9

Outline how knowledge of photoperiodism can be used to induce short-day plants to flower out of season

Answer 9

-gardeners can manipulate plant growth by controlling the plant’s exposure to light
-uninterrupted night length is provided depending on the plant
-short-day plants are covered purposefully with black cloths for 12-15 hours a day to promote gene activation for flowering
-the darkness must be uninterrupted
-period of darkness exceeds critical day length

Question 10

Distinguish essential and non-essential nutrients.

Answer 10

-essential: the human body does not produce the nutrient and must be ingested or absorbed into order for the body to get the needed nutrient
ex: water, vitamins, minerals, dietary fiber
-nonessential: the body is able to synthesize the nutrient by itself and does not need to ingest it
ex: carbs, glucose, sugar, energy can come from protein/fats

Question 11

Discuss the causes and consequences of malnutrition, including protein deficiency malnutrition

Answer 11

-causes: caused by a deficiency/imbalance, or excess of nutrients. overconsumption or illness
-consequences: starvation anorexia (break down of body tissues), obesity (overweight leading to CHD)

Question 12

Outline how leptin controls appetite and the consequences of leptin desensitization.

Answer 12

-adipose fat produced leptin hormone
-leptin acts as an appetite inhibitor on the hypothalamus of the CNS
-reducing food intake
-overconsumption of food produced more leptin, eventually, the body can form desensitization to leptin (mostly in obese people)
-the densentization causes overeating because they cannot recognize they are full
-leptin desensitization comes with age

Question 13

Explain how to determine the energy content of food

Answer 13

-1 calorie is the amount of energy it takes to raise 1g of water one degree
-1 food Calorie= 4.18 kJ
-using a calorimeter: burning a known mass of food under a known measurement of water and measuring how much heat is produced from the burning food and taking the temperate of the water afterward
-mass of water X 4.18kJ X temp of water = energy content of food (joules)

Question 14

Compare and contrast vitamins and dietary minerals

Answer 14

-vitamins: organic, small amounts, long lived in the body
-dietary minerals: inorganic elements, small amounts, used to make specific structures in the body, electrolytes

Question 15

Outline the causes and consequences of vitamin D deficiency and anorexia

Answer 15

-causes vitamin D deficiency: less sun exposure, lack of fish oils, egg yolk, darker skin= more vitamin D exposure than lighter skin
-effect of vitamin D: causes osteomalacia in adults (softening of bones)., rickets in children (irregular bone growth)
-causes anorexia: eating disorder where people limit their intake of food severely, causing starvation
-effects of anorexia: body begins to break down body tissue, heart tissue: blood pressure drops due to reduced volume of blood being pumped. can also developed arthymius(irregular heart beats)

Question 16

Discuss the causes and treatment of PKU

Answer 16

-caused by a chemical inability to metabolize phenylalanine into tyrosine. phenylalanine builds up in the bloodstream due to a lack of enzyme breakdown. can be treated by having PKU patients go on a low-protein diet, limiting the intake of phenylamine. supplements w a formula containing essential tyrosine

Question 17

Outline why food needs to be digested

Answer 17

-large macromolecules are insoluble and contain things, not for humans
-need to be broken down into monomers for easy absorption
-molecules can be reassembled into other products

Question 18

Explain how starch, proteins, and fats (lipids) are digested

Answer 18

(including the names, substrates, products, sites of production, and sites of action of the specific enzymes involved).
-starch: broken down by enzyme amylase into maltose and then broken down maltose into glucose
-proteins: broken down from proteins into fatty acids by protease
-fats: broken down from lipids into fatty acid by emulsification from stomach bile and by lipase

Question 19

Explain the nervous and hormonal mechanisms that control the secretion, volume, and content of gastric sections

Answer 19

• sight a smell of food stimulates the medulla which stimulates the stomach to begin producing gastric juices (via the vagus nerve)
  -after food has reached the stomach, impulse signals from the stretch receptors send a signal to the brain which then sends a signal via vagus nerve to the stomach to begin the production of gastrin
  -gastrin causes sustained release of gastric juices such as HCl
  -if pH becomes too low, gastrin is inhibited by hormones (secretin from the small intestine)
  -small intestine released secretin and CCK to stimulate pancreatic juices

Question 20

Outline the roles of the stomach (in general and in digestion)

Answer 20

-stomach uses chemical and mechiancal processes to digest macromonomers into smaller monomers
-pepsin which is produced in the stomach hydrolyzes proteins
-HCl lowers the stomach pH to denature proteins
-begins protein digestion
-stretch receptors in the stomach stimulate the production of gastric juices and the hormone gastrin
-produces chyme ( a mixture of food being digested and stomach acid)

Question 21

Outline the roles of HCl in the stomach

Answer 21

-HCl is produced in the stomach and lowers the pH of the stomach making it more acidic to denature proteins for protein digestion
-kills bacteria by lowering pH
-Supplies h+ which activates pepsinogen to produce pepsin for hydrolyzing proteins and breaking them down into amino acids

Question 22

Outline the causes, consequences, and treatment of stomach ulcers

Answer 22

CAUSES:
-Heliobacter pylori is a bacteria
-H pylori survives in acidic conditions like stomach acid, by penetrating the mucosa layer of the stomach
-the mucosa protect the stomach by lining in a thick layer of mucus, without the mucosa, the stomach would be exposed to the acidic pH of stomach acids
-H pylori penetrate the mucosalayer causes a hole to form
-H pylori secretes urease to raise the pH and neutralize gastric juices
-also secretes mucinase to break down the mucosa layer of the stomach
-stomach wall is then digested by HCl and stomach acid
TREATMENT:
-antibiotics to get rid of the h pylori
-proton pump inhibitors: PPI’s to reduce stomach acid production
-allowing ulcers to heal over
-PPI’s bind irreversibly to proton pumps to prevent H+ secretion, rasing the pH of the stomach

Question 23

Outline the use of PPI’s to reduce stomach acid secretion

Answer 23

-Proton pump inhibitors are used treatment of ulcers because the inhibitors bind irreversibly to proton pumps to prevent H+ secretion which lowers the overall pH of the stomach
-acidic condition sare maintained by proton pumps in the gastric pit

Question 24

Describe how the structure of a villus is adapted to its function

Answer 24

-MRSLIM
-Microvilli: small folded projections called microvilli to increase the surface area for absorption of glucose
-Rich blood supply: dense capillary network to transport absorbed products
-Single layer: only one cell thick from the lumen to the blood to minimize diffusion distance
-Lacteals: absorbs lipids from the intestine into the lymphatic system
-Intestinal glands: exocrine pits release digestive juices
-membrane proteins- facilitate the transport of digested material into the epithelial cells
-invagantions: increase surface area for maximum diffusion and absorption
-tight junctions: stop lumen and blood from mixing, keep digestive fluids separate
-pinocytosis vesicles: uptake fluids translocate in bulk quickly
-mitochondria: ATP is required for active transport, a large number of mitochondria

Question 25

Describe the methods of transport used to absorb the products of starch, protein, and lipid digestion in the small intestine

Answer 25

-starch: glucose is absorbed by active transport ATP using protein channels against the concentration gradient
-amino acids: also absorbed via active transport
- lipids: fatty acids are absorbed via diffusion, easily pass along the hydrophobic membrane
-sugar: fructose is absorbed by facilitated diffusion pumped through protein channels
-endocytosis: form a vesicle around large molecules

Question 26

Distinguish between exocrine and endocrine glands (with regard to their structure and function)

Answer 26

EXOCRINE
-produce and secrete substances via a duct onto an epithelial surface
-uses ducts to release hormones
-ex: sweat glands, the lumen of the digestive track
-salivary glands, gastric glands, pancreatic glands
ENDOCRINE:
-ductless gland, release hormone directly into the bloodstream, ex: pancreas, ovaries
-hormones bind to specific receptors to activate certain cells and tissue for bodily function
-used to regulate body functions

Question 27

be able to identify an exocrine gland in micrographs based on recognition of structural features too.

Answer 27

-shaped like a sideways key hole
-basement membrane
-duct cells
-secretory cell

Question 28

Outline the benefits of a diet rich in fiber.

Answer 28

-more fiber= faster rate of material movement
-decreases hunger due (prevents obesity)
-absorbs water for more fluid transport of chyme down digestive track
-celluose ex
-provides bulk
-lowers risk of colon cancer

Question 29

State which substances are egested by the human body.

Answer 29

-BELCH
-bile pigments
-epthiealcells
-ligin
-cellulose
-bacteria

Question 30

Outline the effects of the cholera toxin.

Answer 30

-a pathogen that infects the intestine
-causes dehydration and dierrha
-chlorella releases toxin to bind to receptors on the epithelial membrane.
-activates ion channels that pump out Cl of the cells and into the intestine
-water follows the ions being pumped out of the cells due to the concentration gradient
-removing water from the interior of the cells
-water is then flushed out of the lumen via egestion and not absorbed

Question 31

Explain how the pancreas maintains homeostatic levels of glucose in the blood

Answer 31

-the pancreas acts as a exorine gland which allows hormones to be directly released into the bloodstream
-produces hormones to control blood glucose levels
-beta-cells are produced when blood sugar/glucose levels are high
-insulin causes cells to uptake glucose, cell respiration rates increase, causing a break down of glucose
-glucose is also taken to liver and stored at glycogen as a larger molecule to take it out of the bloodstream
-alpha cells are produced when blood sugar is low and produce glucagon
-glucagon breaks down glycogen storage in the liver (stimulating hepatocytes) into glucose and releases it into the bloodstream to increase blood sugar levels
-antagonistic hormones, insulin beta, glucagon alpha

Question 32

Explain the causes, consequences, and treatment of Type I and Type II diabetes

Answer 32

TYPE I:
-early onset
-genetic or illness caused
-no insulin produced
-must get insulin injections to regulate blood glucose levels
TYPE II:
-adult onset
-developed resistance to insulin
-insulin receptors are fewer
-related to obesity, poor diet, lack of exercise,
controlled by managing diet, exercise, smaller meals, and reduced sugar intake
SYMPTOMS
-high blood sugar, glucose in the urine, weight loss, increased thirst, fatigue

Question 33

Outline the dual supply of blood to the liver.

Answer 33

• dual blood supply: blood enters from the hepatic portal vein and the hepatic artery
  -hepatic portal vein delivers nutrient-rich blood from the lumen, gut to liver
  -hepatic artery supplies oxygen-rich blood needed for cellular respiration, from the heart to liver-

Question 34

Explain how the liver regulates nutrient levels in the blood (including nutrients that are stored by the liver)

Answer 34

-liver store glucose as glycogen, a compound made up of multiple glucose molecules
-Kupfer cells in the liver break down hemoglobin into heme and a globin group
-iron from the heme group, is carried to bone marrow to produce new hemoglobin groups for new red blood cells
-vitamin a, vitamin d, iron, stored in the liver
-liver detoxifies blood using sinusoids
-excess cholesterol is converted into bile salts for bile (secreted by the liver)
-liver contains all essential vitamins, minerals, and nutrients needed to maintain homeostasis regardless of diet
-fats: excess proteins and carbs are broken down into fatty acids and triglycerides and are stored to make phospholipids
-proteins: liver uses amino acids to make plasma proteins, amino acids cannot be stored

Question 35

Explain how the liver breaks down and recycles the components of erythrocytes (red blood cells).

Answer 35

-erythrocytes have a lifespan of 120, they rupture
-Kupfer cells ingest erythrocytes in the sinusoid of the liver
-hemoglobin is split into heme and an iron group by peptidases
-heme is broken down further into iron which is then transported to bone marrow to make more new hemoglobin for new red blood cells
-globin is broken down into amino acids
-bilirubin becomes a part of bile as it is bile pigment or it is egested from the alimentary canal

Question 36

Outline the production of bile and the causes and consequences of jaundice.

Answer 36

-bilirubin, bile pigment, is produced from the breakdown of erythrocytes
-bile is stored in the gallbladder and is used
-bile is made in the liver
-bile is used to emulsify fats
Causes of jaundice: high level of bilirubin/bile in the body and bile pigment leaks out into the bloodstream, liver disease, gall stones, bile duct blockage
Consequences:
-yellowing skin, yellowing eyes, itchiness

Question 37

Label the structures of the human heart (and know the function of each).

Answer 37

-superior vena cava
-right atria
-AV values
-right ventricle
-semilunar values
-pulomnarty artery

-puliomary veins
-left atrium
-av values
-left ventricle (thicker ventricle)
-semi lunar value
-aorta

Question 38

Outline the flow of blood to, through, and from the heart (including pulmonary and systemic circulation, and the benefits of the double circulation).

Answer 38

-superior vena cava brings in oxygenated blood into the right atria
-blood fills the right atria, as blood fills, AV values open, blood flows from the right atria to the right ventricle.
-as blood fills the ventricles, once pressure in the ventricles is greater than pressure in the right atria, ventricles contract, and AV values snap shut (lub sound)
-pressure increases in the ventricles , semilunar values open,
-blood is then pushed out of the heart (pulomary artery if right ventricle, aorta if left ventricle0)
-semilunar values shut due to decreased pressure in ventricles (dub sound)
-double pump: that way deoxygenated blood and oxygenated blood do not mix
-deoxy is from the veins

Question 39

Describe the myogenic, autonomic (medulla), and endocrine (adrenal gland) control of the heartbeat.

Answer 39

-myogenic control: the heart controls itself via the SA node
-in the right atrium, there is a group of specialized cells known as the SA node
-SA node acts as a pacemaker for the heart as it regulates electrical stimulation of the heart beat
-the heart can beat without signal from the nervous system
-SA node sends an impulse down the right atrium to the AV node.
-AV node delays 0.1 second before sending the signal to ensure maximum blood flow
-AV node sends signal to the bundle of his at the ventricles, and down the purkinje fibers.
-autmatic control of the heart beat comes from the medulla in the central nervous system
-medulla monitors CO2 and pH of the blood, if CO2 rises (ph lowers) then medulla senda signal via cardiac nerve to the heart to release nonrepehinrine to stimulate the SA node more frequently, causing heart rate to increase
-as CO2 lowers and ph goes back to normal, then medulla send a signal via vagus nerve to release acetylcholine causing the heart rate to slow due to SA node firing less frequently.

Question 40

Describe the role/ functions of valves in the human heart.

Answer 40

-valves prevent the backflow of blood from the ventricles to the atria
-valves open and close in response to pressure changes in the atria and ventricles
-allows the heart chambers to fill and empty
-control the timing of blood flow in the cardiac cycle

Question 41

Explain the events of the cardiac cycle

Answer 41

(including systole and diastole of the atria and ventricles, the roles of the SA and AV nodes/ bundle of His/ purkinje fibers, the reasons for a delay between atrial and ventricular contractions, and the heart sounds).
-duration of one heartbeat:
1. blood flows freely from the atria to the ventricles (diastole)b/c of slightly higher pressure in the atria
2. SA node fires, causing both atria to contact, (atrial systole)
3.AV node is then activated, it is slightly delayed to allow the ventricles to fill with blood,
4. AV node fires, causing both ventircle sto contract (ventricle systole)
5. increased pressure in the ventricles causes the AV values to close (lub sound)
6. large pressure in the ventricles causes the semilunar values to open, allowing blood flow out of the ventricles
7. semilunar values close due to increased pressure in the pulmonary artery and aorta
8. all values are closed and blood flows freely into the atria (atrial distole)
9. cardiac cycle repeats

Question 42

Identify (on a graph) and outline pressure and volume changes and sounds in the left atrium, left ventricle, and aorta during systole and diastole.

Question 43

Explain how the structure of cardiac muscle cells is adapted to their function.

Answer 43

-highly branches to increase surface area and point of contact
-intercalated discs: regions between the plasma membrane of adjacent cells
-discs contain gap junctions which allow cytoplasm to flow freely to allow electrical signals to be transmitted between cells
-contain more mitochondria because of lifelong contractions

Question 44

Identify and diagram the P, QRS, and T waves in an ECG trace and explain what happens in the heart during each.

Answer 44

-p: first bump, represents atrial contraction (SA node firing)
-QRS: ventricle systole ( contraction of the ventricles)
-T: slight bump after QRS: ventricle diastole (relax, heart is in diastole as blood flows freely into the atria)
-electrocardiogram

Question 45

Calculate heart rate using an ECG trace

Answer 45

-R is one peak of the QRS to the next peak of the QRS graph
-count how many seconds between the R to R, convert to minutes
BPM: beats per minute

Question 46

Outline the factors that can affect heart rate.

Answer 46

-controlled by both nervous and hormonal signals
-exercise, age, disease
-hormone= release of norepinephrine
-nervous= vagus nerve

Question 47

Explain the use of a defibrillator and artificial pacemaker.

Answer 47

-a defibrillator is used when the heart is experience arrhythmias (irregular heartbeat)
-it is a device used to deliver an electrical shock that depolarizes a person’s chest in hopes of re-establishing a normal rhythm via the SA node
-artificial pacemaker is place inside the heart to deliver small electrical stimuli to regulate heartbeat if detected

Question 48

Explain how the structure of arteries, veins, and capillaries are adapted to their function.

Answer 48

ARTERIES:
-carry blood away from the heart
-larger to prevent rupturing
-thicker due to high pressure to prevent rupturing
-narrow lumen to maintain high pressure
-no valves
VEINS:
-carry blood toward the heart
-larger lumen low pressure to increase blood flow
-thin walls (to allow skeletal muscles to squeeze blood through)
-larger lumen due to low pressure
-valves are used to prevent backflow of blood due to low pressure
CAPILLARIES:
-very small, one only cell thick diameter to allow easy diffusion of materials into the blood stream
-have pores to allow exchange of materials
-no values
-narrow lumen to SA/V ratio

Question 49

Identify vessels as arteries, veins, or capillaries in diagrams or micrographs based on the structure of their walls.

Answer 49

-arteries: small lumen with thick walls
-veins: larger lumen with thin walls
-capillaries: very small with pores

Question 50

List the components of blood and what is transported by the blood.

Answer 50

-blood contains erythrocytes
-plasma (fluid of blood)
-white blood cells
-platelets
-blood transports nutrients: glucose, oxygen and co2, heat, urea, hormones, antibodies)

Question 51

Explain how materials are exchanged between the capillaries and tissues (and know which SPECIFIC materials would go INTO cells/ tissues from the blood and which SPECIFIC materials would come OUT of cells/ tissues and go into the blood)

Answer 51

-molecules move via diffusion and the concentration gradient
-nutrients, glucose, oxygen move into tissues
-gCas exchange between capillaries and tissues
-wastes move from tissues to capillaries, urea, nitrogen, co2, excess water

Question 52

Outline the role of valves in veins.

Answer 52

-values are used to prevent backflow of blood within the lumen of the vein.
-due to veins low pressure, blood can backflow, so values prevent that from occurring
-maintain one way flow

Question 53

State what atherosclerosis , and explain the process of how it can cause occlusions and/ or clot formation in the coronary arteries.

Answer 53

-atherosclerosis of the coronary arteries is the cause of coronary heart disease
-CHD is caused by atherosclerosis of the coronary arteries
-atherosclerosis is the build of up pf plague within coronary artires, blocking blood flow and causing increased blood pressure in the arteries
-occlusion occur when the artery can not longer supply a minimally healthy amount of blood to the tissue

Question 54

Explain the consequences of occlusions of the coronary arteries and the risk factors for developing CHD.

Answer 54

-prevents a healthy amount of blood flow to tissues
-increased blood pressure
-damages endothelial wall
-harden of artery walls
-reducing elasticity
-reduction of oxygen to the heart muscle because of CHD which affects the coronary arteries
-Age bc of less elastic
-Genetics
-Obesity
-Diseases
-Diet
-Exercise
-Sex (male or female
-smoking= increased blood pressure

Question 55

Outline how to measure blood pressure, the difference between systolic and diastolic pressures, and the causes and consequences of hypertension.

Answer 55

-systolic: occur during contraction, blood pressure on arteries when a contraction
-diastole: resting period occurs during relaxation, blood pressure when heart muscles relax
-measuring blood pressure: using cuff pressure to block blood pressure, systole is when sound occurs, diastole is when there is no more sound
-systole/diastole

Question 56

Describe how the structure of the alveoli is adapted to its function (make sure to include type I and type II pneumocytes as well).

Answer 56

T: thin walls, allow for easy diffusion of material exchange between capillaries and the lungs, only one cell thick
R: rich capillary network: to maintain high O2/CO2 concentration gradient around the lungs to maintain gas exchange
I: increased surface area to volume ratio bc of small spherical shape,
M: moist prevents alveoli from collasping and sticking together, and also allows gases to dissolve
-type I pneumocytes: very flat to minimize diffusion distance and increase surface area for gas exchange, cells do not divide
-type II pneumocytes: secrete a surfactant to decrease the surface tension between alvelio, all expand at the same rate

Question 57

Identify type I and type II pneumocytes and red blood cells in electron micrographs of the alveoli.

Answer 57

Type II are bulker and are more square
Type I are small and thin

Question 58

Distinguish cellular respiration, ventilation, and gas exchange.

Question 59

Explain the process of gas exchange in the alveoli of the lungs and the role of the ventilation system in maintaining concentration gradients of CO2 and O2 between the alveoli and the capillaries surrounding them.

Answer 59

-gas exchange is a passive process (diffusion)
-high concentration of O2 in the alveoli
-high concentration of CO2 in the capillaries/blood system
-CO2 follows the concentration gradient and diffuses out of the capillaries and into the alveoli
-O2 diffuses out of the alveoli and into the bloodstream
-the ventilation system maintains this concentration gradient between O2 and CO2
-allows a continual cycle with air in the lungs and the air in the atmosphere
-ventilation is the exchange of air in the lungs with the air in the atmosphere

Question 60

Outline the processes of inspiration/ inhalation and exhalation (including the roles of antagonistic muscles)

Answer 60

-inhalation is the breathing in of atmospheric air, as air enters the lungs, the diaphragm flattens and contracts, while the external intercostal muscles contract by pulling the ribs up
-antagonistic muscle pair
-diagram and external intercostal muscles
-thoracic cavity volume and lung volume increase

exhalation:
-diaphragm relaxes and curls upwards, ab muscles contract along with internal intercostal muscles
external intercostal muscles relax
-lung volume decreases

Question 61

Outline the causes and consequences of emphysema and lung cancer (and the treatments of emphysema too).

Answer 61

-causes: smoking, air pollution,
-White blood cells come to help alveoli but they secret elastase which breaks down the elastic fibers in alveolar walls
-consequences: break down of alevlio elasticity, break down, rupturing, less O2 reaching the bloodstream
-treatments: bronchodilators, surgery elastase enzyme supplements

Question 62

Explain the effects of increased exercise (changes in CO2/ pH) on ventilation rate (and tidal volume), and explain how ventilation rate is controlled.

Answer 62

-exercise increases metabolism
-this increase CO2 in the bloodstream which lowers blood pH levels
-chemoreceptors in the respiratory part of the brain signal the medulla oblongata
-the medulla then changes in pH and send a signal via the vagus nerve to the diaphragm and external intercostal muscles to begin contracting faster
-increase the ventilation rate
-as ventilation rate increases CO2 levels drop, pH in the blood returns to normal, and eventually breathing rate decreases to normal
-using negative feedback
-invoulntary

Question 63

Outline how to use a spirometer to measure ventilation rate.

Answer 63

-count the number of breaths per minute
-spirometer measured the volume of gas expelled or inhaled per breath
-shows tidal volume, total amount of O2 in one breath
-wave graph

Question 64

Calculate ventilation rate and tidal volume using spirometer data and make conclusions using that data.

Question 65

Describe how the structure of hemoglobin and myoglobin are related to their functions and their oxygen dissociation curves.

Answer 65

-hemoglobin, four polypeptide compound
-each polypeptide has one heme group that bind reversibly to oxygen
-cooperative binding: one O2 changes the chape of hemoglobin to make it easier for more O2 to bind, higher affinity for oxygen in high oxygen rich areas
-hemoglobin s-shaped curve:cooperative binding with oxygen molecules
-when oxygen concentration (partial pressure) is low then hemoglobin has a low affinity for oxygen because oxygen is being released from hemoglobin to bind with cells and tissues
-when oxygen concentration is high, then hemoglobin has a higher affinity for oxygen,taking up oxygen from the alveoli in the lungs
-Myoglobin:
-no cooperative binding, can only carry one O2
-stored in muscles to act as an oxygen reserve,
-able to provide O2 in desperate situations
-higher affinity for O2
-not an s shaped curve, shifted all the way to the left

Question 66

Diagram and explain the oxygen dissociation curves for adult hemoglobin, fetal hemoglobin, and myoglobin.

Answer 66

-myoglobin: shift all the way to the left because of no cooperative binding, higher affinity for oxygen than hemoglobin,
-acts as oxygen reserve for muscles
-can only carry one oxygen
-fetal hemoglobin:
-transfer of oxygen from the mother’s placenta to the fetus
-slightly different shape
-higher affinity for o2 than adult
-shifted left bc of higher affinity
-ensures oxygen from placenta will reach fetal capillary system
-adult hemoglobin
-s-shaped curve because of cooperative binding
-high affinity for oxygen in high oxygen concentrations

Question 67

Diagram and explain the Bohr shift (remember that “explain” means you include the REASONS/ WHY’s in an answer too).

Answer 67

-Bohr shift occurs during respiration
-respiring tissues require more O2 and release CO2, which lowers the blood pH-
=lower pH means decreases of hemoglobin’s affinity for oxygen
-Shift to the RIGHT
-excess CO2 breaks down by red blood cells into carbonic acid
-carbondic acid breaks into H+ and H3O+ ions
-H+ bind to hemoglobin causes oxygen to be released and put into respiring tissues

Question 68

Explain WHY and how the body adapts to gas exchange at high altitudes (including pros and cons of high altitude training).

Answer 68

-red blood cell production increases, more hemoglobin, more oxygen being transported
-red blood cells are produced with more hemoglobin inside of them, a higher affinity for oxygen
-vital capacity increased (more surface in the lungs to breathe air in)
-muscles produce more myoglobin for the storage of oxygen
-larger chest size, greater surface area (if permanently living)
PROS: increased performance and endurance
CONS: unfair advantage, altitude sickness, effects are only temporary

Question 69

Describe the different ways that carbon dioxide is carried in the blood.

Answer 69

• Carbon dioxide is carried in solution and bound to hemoglobin in the blood
  -dissolved in blood plasma
• Carbon dioxide is transformed in red blood cells into hydrogen carbonate ions
  -carbonic anhydrase combines CO2 and water
  -carbonic acid is broken down into H+ and HCO+3
  -t: Bicarbonate ions are pumped OUT of erythrocytes and Cl- ions are pumped in
  . Bicarbonate ions in blood plasma combine with sodium ions in the blood plasma(NaHCO3) – these
  are carried to the lungs
• H+ ions in the erythrocyte lower the
  pH, causing hemoglobin to release
  oxygen (to respiring cells/ tissues)
  -Hemoglobin absorbs/ binds excess H+
  ions to buffer/ maintain pH in the
  erythrocyte
  -In lungs, HCO3- pumped back into
  RBC’s and entire process reversed

Question 70

Outline how blood pH is maintained (and know the range of “normal” pH in the body).

Answer 70

-normal pH range= 7.4
-via negative feedback by the endocrine and nervous system

Question 71

Draw and label a motor neuron (and know the function of each structure).

Answer 71

-dendrites: receive a chemical signal from other neurons
-nucleus: contains DNA for the neuron cell
-axon: long nerve fibers, carrying signals away from the cell body to the axon terminal
-myelin sheath: Schwann cells (made of lipids uses to increase the speed of a signal down an axon), nodes of Ranvier (gaps in between the axon which allows for certain Na+ channels to open)
-axon terminal (neurotransmitters are released for synaptic transmissions

Question 72

Describe the role of the sodium-potassium pump in maintaining the resting potential.

Answer 72

-actively pump 3 Na+ out of the neuron cell and pump 2K+ into the neuron cell to create a negative resting potential (-70mV)

Question 73

Explain how an impulse (action potential) is propagated down the length of a neuron (including the role of myelin).

Answer 73

-the resting potential of a neuron membrane is negative (-70mv) because of 3 Na+ going out of the membrane and 2 K+ going into the membrane
-electrical impulses in a neuron are action potential
- as an action potential travels down the axon, Na+ channels open, allowing Na+ into the cell which causes depolarization and makes the membrane potential more positive
-myelin sheath allows the action potential to travel faster down the axon b/c only na+/k+ channels at the nodes of Ranvier are able to open. this is because Schwann cells which are made of lipids block the other na/k channels along the axon
-also saltatory conduction, requiring less ATP to send a signal

Question 74

Analyze an oscilloscope trace showing changes in membrane potential during and after an action potential.

Answer 74

-resting potential = -70mV
-threshold potential= -55mV
-depolarization: occurs when an action potential reaches the axon of a neuron. (wave going up)
-repolarization= wave going down, K+ channels open, Na+ channels close
-hyperpolarization: going under the resting potential
-goes back to resting potential

Question 75

Explain the process of synaptic transmission at the neuromuscular junction (including the role of acetylcholinesterase)

Answer 75

-Ach is a neurotransmitter used in motor neurons to stimulate muscle contraction
-AcHE is an enzyme used to break down Ach into acetyl and choline in the synapse (released by the presynaptic cell)
-Ach binds to receptors on the muscle membrane which allows Na+ channels to open and Na+ ions diffuse into post-synaptic muscle fibers
-Choline is reuptake by the presynaptic cell to make more Ach

Question 76

Discuss the use of neonicotinoid pesticides (pros and cons) and describe how they affect synaptic transmission in insects.

Answer 76

Neonicotinoids block acetylcholine receptors in an insect’s CNS from binding to acetylcholine released from a presynaptic neuron. the lack of acetylcholine leads to insect paralysis as the muscle cannot contract to extend
-eventually leading to death
-

Question 77

Label a diagram or x-ray of the human elbow joint (and know the function of each structure, including the movements of flexion and extension).

Answer 77

-humerus: connects elbow bones together
-bicep: Muscles that contract to provide flexion (bending) of the arm
-tricep: a muscle that contracts to provide the extension (straightening) of the arm
-BICEP & TRICP ARE ANTAGONISTS
-joint capsule: promotes stability, surrounds the joint cavity
-synovial fluid: reduces friction
-cartilage: reduces friction between bones
-radius: acts as a lever for the bicep
-ulna: acts as a lever for the tricep

Question 78

Outline the structure of skeletal muscle.

Answer 78

-striated muscles
-force movement by shortening the length of the fibers
-can only actively shorten
-exist in antagonistic pairs
-composed of muscle cells
-a LONG fiber,
-many cells that have fused together
-lot’s of nuclei
-lot’s of mitochondria for cellular respiration and consumption of ATP
-contain special endo reticulum
-sarcoplasm reticulum contain lot’s of calcium ions for muscle contraction

Question 79

Draw and label a sarcomere (and be able to identify the structures of a sarcomere in diagrams or micrographs).

Answer 79

-actin (thin filament)
-myosin (thick filament)
-z line to z line
-I band then A band H zone
-full sarcomere label

Question 80

Explain the process of muscle contraction.

Answer 80

-nerve impulses reaches the synapse of a neuromuscular junction (between a neuron and a motor cell)
-Ach is released into the synaptic cleft
-Ach binds to the receptors on the motor neuron membrane
-sodium channels open in response on the sarcolemma of the muscle cell, causing calcium channels to open an released ca+
-ca+ ions bind to tropinin on actin filaments causing tropomyosin to move off of the myosin binding sites on actin
-ATP is hydrolyzed providing energy for myosin heads on myosin filament to form cross-bridges with the actin filament on the mysoin binding sites
-myosin heads change chape causing actin filaments to be pulled towards the center
-shortening the sacromere, causing muscle contraction
-myosin filament and actin filament slide past one another
-

Question 81

Analyze electron micrographs of sarcomere structure to determine if muscle is relaxed or contracted.

Answer 81

Relaxed: sarcomere is longer, light and dark bands
Contracted: sarcomere is short, mostly dark bands

Question 82

State a null and alternative hypothesis for an experiment.

Question 83

Calculate a corrected p-value for an ANOVA statistical test.

Question 84

Analyze the results of an ANOVA statistical test (by comparing F and F-critical values).

Question 85

Analyze the results of subsequent t-tests in an ANOVA statistical test.