module 2+3: evil chris questions>;0

Question 1

an animal having an alimentary tract with two openings instead of one has the advantage of:

Answer 1

1. continuous feeding
2. one way flow of food and waste
3. evolution of special digestive processes localized along the tract

Question 2

the order of digestion of food in the alimentary canal, starting from the oral cavity is:

Answer 2

carbohydrates > proteins > nucleic acids > fats

Question 3

explain why food has to be digested before absorption can occur:

Answer 3

1. food can only be absorbed after it has been broken down into small molecules
2. food has to be broken down into simple molecules so that the animal taking in the food can either metabolize or use the molecules to build up its own body components specific of the species

Question 4

what happens if too much gastrin is produced?

Answer 4

too much HCL break down mucus and cause ulcers

Question 5

following the consumption of a highly salty meal, which of the following would be a likely consequence in a human?

Answer 5

decreased secretion of aldosterone

Question 6

osmoconformers have body fluids that are ______ to the environment. osmoregulators have body fluids that are_____ to the environment

Answer 6

isotonic, hypotonic or hypertonic

Question 7

sharks living in a marine environment compensate for their hypotonic system relative to the sea by

Answer 7

excreting massive amounts of water

Question 8

aquatic organisms that are hypotonic relative to the surrounding water tend to

Answer 8

gain salts from the environment

Question 9

when placed in a hypotonic (less solute) solution what occurs to a cell

Answer 9

an animal cell would burst but a plant cell would not

Question 10

the sodium-potassium pump transfers

Answer 10

3 sodium ions out and 2 potassium ions in

Question 11

the most important structure involved in concentrating urine within the nephron is

Answer 11

loop of henle

Question 12

in the kidney the correct sequence of formation of urine involves the following processes

Answer 12

glomerular filtration, reabsorption, tubular secretion

Question 13

reabsorption of chloride ions from the glomerular filtrate in the kidney tubule is carried by

Answer 13

diffusion

Question 14

explanation for a marine star dying after being placed in fresh water

Answer 14

sea star is hypertonic to freshwater and could not osmoregulate

Question 15

why do sodium ions enter the cell when voltage-gated sodium channels are opened in neurons

Answer 15

1. the sodium concentration is much higher outside the cell than inside
2. sodium ions are attracted to the negatively charged interior

Question 16

an action potential is generated by

Answer 16

massive influx of sodium ions

Question 17

within a neuron, information moves from

Answer 17

dendrite to cell body to axon

Question 18

the chemical that diffuses across the synaptic gap, establishing communication between two neurons is called

Answer 18

neurotransmitter

Question 19

how do myelin sheaths increase the speed with which action potentials are propagated along an axon?

Answer 19

they cause action potentials to “jump” down the axon rather than travel in a continuous path along every site on the axon.

Question 20

the resting potential of a neuron is due mostly to

Answer 20

open potassium channels

Question 21

short interval of time during which restimulation after action potential is not possible is called

Answer 21

hyperpolarization

Question 22

whether a synapse is excitatory or inhibitory depends on the

Answer 22

type of neurotransmitter

Question 23

after the action potential begins, sodium voltage gated channels are most likely

Answer 23

open

Question 24

in saltatory conduction

Answer 24

an action potential jumps along a myelinated axon from one node of ranvier to the next

Question 25

action potential event sequence

Answer 25

1. neuron is stimulated at the dendrites
2. sodium gates open then close
3. potassium gates open
4. the cell is fully repolarized
5. the cell is fully depolarized
6. the neuron is in a polarized resting state

Question 26

the specificity of a hormone is due to

Answer 26

specialization of target-organ receptors

Question 27

paracrine communication refers to interactions between cells resulting from

Answer 27

direct contact of neighbouring cells at tight junctions

Question 28

many nonsteroid hormones act upon their target cells by causing

Answer 28

the activation of adenylate cyclase

Question 29

the endocrine system

Answer 29

1. releases chemicals into the bloodstream for distribution throughout the body
2. releases hormones that alter the metabolic activities of many different tissues and organs
3. produces effects that can last for hours, days or even longer
4. can alter gene activity in cells

Question 30

smooth muscle differs from both cardiac and skeletal muscles in that

Answer 30

membranes of smooth muscle cells are depolarized by stretching

Question 31

A novel species of butterfly has evolved the ability to attack birds that prey on it, injecting cardioglycosides it extracts from the milkweed on which it feeds. True or false, In this situation, the cardioglycoside would be considered both a venom and a poison.

Answer 31

true

milkweeds and cardioglycosides are toxic and that some animals accumulate toxins as poisons to protect themselves from predators

Question 32

T or F: Birds that fly between north and south might use a magnetic compass but animals that move up and down cannot use magnetic fields to navigate.

Answer 32

false

Question 33

T or F: Statocysts only work in animals that are neutrally buoyant because the statoliths in the statocysts are the same density as water.

Answer 33

false

Question 34

In a hair cell receptor, the key point is that the hairs on the apical end of the cell are different lengths. This permits the cells to detect a direction of fluid flow, such as anterior to posterior. True or false: If the hair cells were the same length, they could detect fluid movements in both direction.

Answer 34

false

the ability to detect the movement would require there to be a change in distance between the tips, and the only way that happens is if the hairs differ in length.

Question 35

Cayenne peppers taste hot because they bind to thermoreceptors and cause local heating.

Answer 35

false

no local heating involved at all

Question 36

Oligodendrocytes produce the myelin that covers motor neurons in flight muscles of insects.

Answer 36

false

Question 37

The CNS is subdivided between the Afferent neurons and efferent neurons. The efferent neurons include the motor system and autonomic system, which includes the sympathetic, parasympathetic and enteric divisions.

Answer 37

false

afferent and efferent neurons are in the peripheral nervous system. That carry information to/from the CNS.

Question 38

Astrocytes are a type of glial cells in the central nervous system that have a number of support functions, including maintenance of the blood-brain barrier.

Answer 38

true

Question 39

The AMPA receptor is an ion channel but a NMDA receptor is not an ion channel.

Answer 39

false

Question 40

Mammals use the hormone gonadotropin-releasing hormone (GnRH) from the hypothalamus to trigger the release of FSH and LH from the pituitary, which alters hormone production by the gonads. True or false. All of these hormones are tropic hormones.

Answer 40

true

Question 41

In mammals, after the follicle releases the ovum, the next steps for the follicle depends on whether the ovum is fertilized and implants in the uterine wall. True or false: The remnants of the follicle receive their instructions via paracrine stimulation.

Answer 41

false

Question 42

The placenta is composed of many cells. Any two cells would share at least half their genes, but not all cells would share the same genome.

Answer 42

true

Question 43

Insects use the antagonistic hormones juvenile hormone and ecdysone to regulate development. Both hormones are derived from the pathway used to produce cholesterol, and both are hydrophobic. True or false: If you were looking to characterize their receptors, you would be well advised to begin the analysis looking at the proteins in the cell membrane of target tissues.

Answer 43

false

Question 44

Trehalose is produced from the breakdown of glycogen, which is usually present as large branched polymers of glucose. True or false, the osmolarity of a solution with 1,000,000 glucose molecules would be the same regardless of whether they existed as a 500,000 trehalose molecules or 1 glycogen particle.

Answer 44

false

Question 45

An important part of the control of blood glucose levels is the secretion of insulin and glucagon by the pancreas. True or False: If glucose is high, insulin will reduce the secretion of glucagon, an example of a negative feedback pathway.

Answer 45

false

Question 46

The epithelial lining of the gut is composed of smooth muscle cells that are arranged either longitudinal or circular layers.

Answer 46

false

Question 47

The lumen of the small intestine is made acidic by the actions of a proton pump in parietal cells.

Answer 47

false

Question 48

Leptin is a hormone that increases appetite. When animals have low leptin synthesis, low levels of leptin receptors, or insensitive leptin receptors, this signaling pathway is impaired and animals lose their appetite.

Answer 48

false

Question 49

A new snake is discovered with a venom that targets the CaATPase in the SR of skeletal muscles. True or false. In the presence of the venom, the skeletal muscle could contract but would be unable to relax.

Answer 49

true

Question 50

Lactation, as we define it, is possible from the repurposing of existing genes, evolving new or different functions in mammals. These mammalian genes include alpha-lactalbumin, lactotransferrin, lactose, and casein.

Answer 50

false

Question 51

The p50 of hemoglobin for oxygen is higher under conditions that cause a decrease in oxygen affinity of hemoglobin.

Answer 51

true

Question 52

The pathway for blood goes from left ventricle to pulmonary artery, pulmonary vein and back to the right atrium.

Answer 52

false

Question 53

The contraction phase of the heart is systole and the relaxation phase is diastole. Thus, diastolic blood pressure is the pressure in the circulation when the heart has filled but not yet ejected the blood.

Answer 53

true

Question 54

A cow is forced to run on a treadmill. Researcher find that when it runs, its respiration rate doubles, its hemoglobin oxygenation does not change, its cardiac output doubles, and its heart rate also doubles. Based on these observations, you would predict that the stroke volume doesn’t change.

Answer 54

true

Question 55

In mammals, myoglobin is the most important carrier of oxygen and carbon dioxide in the blood.

Answer 55

false

Question 56

Frogs can breathe oxygen across the skin, as well as via the lungs. If a frog is in hypoxic (low oxygen) water, it would lose oxygen from the body across the skin unless there was a means to direct blood away from the skin capillaries.

Answer 56

true

Question 57

Countercurrent systems increase the efficiency of exchange between two systems flowing in the same direction.

Answer 57

false

Question 58

Hemoglobin shows cooperative oxygen binding, meaning that as oxygen concentration increases, it is easier for the hemoglobin molecule to bind a second oxygen once the first one is bound.

Answer 58

true

Question 59

You have two solutions: 1 M glucose and 0.25 M NaCl. The glucose solution has a higher osmolarity.

Answer 59

true

Question 60

Salmon hatch in freshwater, and after a period of time as small parr, they remodel their physiology in preparation for the transition to seawater (smoltification). The smolts then migrate to seawater. Thyroid hormone promotes the synthesis of Na K ATPase- the sodium pump- which has an important role in excretion of excess Na from the body. True or false: You would expect thyroid hormone to be higher in parr than smolts.

Answer 60

false

Question 61

Osmolarity of body fluids is important to regulate because the membranes of cells are impermeable to solutes and water

Answer 61

false

Question 62

Osmoregulators control the osmotic gradients between the environment and the extracellular fluid, but their cells have the same osmolarity as the extracellular fluid.

Answer 62

true

Question 63

The adaptive immune system includes both responses mediated by cytotoxic cells and responses of extracellular proteins that are present in body fluids.

Answer 63

true

Question 64

Consider a single B cell. It may make an antibody or a receptor that binds the same antigen. True or False: The antibody and receptor have the exact same sequence, and the only difference is whether the B cell secretes the protein.

Answer 64

false

Question 65

Immunization works by stimulating memory cells to produce abundant antibody.

Answer 65

false

Question 66

Cytotoxic T cells use their receptors to bind onto infected cells that display the antigen of the pathogen that infects it.

Answer 66

true

Question 67

In contrast to passive transport, all forms of active transport require ATP as a source of energy.

Answer 67

false

Question 68

Depolarization of a neuron occurs when Na channels open and Na rushes out of the cell.

Answer 68

false

Question 69

Striated muscles have thick and thin filaments whereas smooth muscle does not.

Answer 69

false

Question 70

Ectotherms regulate a combination of heat production and heat loss to ensure that their body temperature remains within a narrow range.

Answer 70

false

Question 71

You are comparing two cells at rest, both with the same internal ion concentrations and in a solution with the same external ion concentrations, and under these conditions the equilibrium potential for K is the same, -90 mV. They also have the same collection of ion channels, but in cell A, the K channels are open and in cell B the K channels are closed. The resting membrane potential for cell A is -60 mV. It is likely that the resting membrane potential for cell B is greater than that in cell A.

Answer 71

true

Question 72

The following elements of a muscle are arranged in increasing order of size: thin filament, thick filament, sarcomere, myofibril, myofiber, muscle.

Answer 72

true

Question 73

In comparing two animals, species A and species B. Species A has a troponin with a higher affinity for Ca. This would likely result in a muscle that contracts faster following excitation, if all other components are similar between species.

Answer 73

true

Question 74

Many processes are dependent on body size, due in part to the fact that as animals get larger, their surface area increases more than does their volume.

Answer 74

false

Question 75

During an action potential, the membrane potential first moves toward the equilibrium potential for Na+, then at peak depolarization, moves away from the equilibrium potential for Na+, toward the equilibrium potential for K+.

Answer 75

true