Priciples Of Biology 2: Humans

Front 1

When comparing a mouse to an elephant, the mouse has a _____ surface area to volume ratio and a _____ mass-specific basal metabolic rate.

Back 1

*higher; higher
-lower; lower
- higher; lower
- lower; higher

Front 2

A homeostatic set point is best described as _____.

Back 2

- a structure that senses some aspect of the
external or internal environment
- a structure that helps restore a desired internal
condition
* a normal or target value for a controlled variable
- a structure that evaluates the incoming sensory
information and "decides" whether a response is
necessary to achieve homeostasis

Front 3

How does a selectively permeable membrane affect diffusion?

Back 3

- All molecules move from a lower concentration to a higher concentration.
* Only some molecules move from a higher concentration to a lower concentration.
- Only some molecules move from a lower concentration to a higher concentration.
- All molecules move from a higher concentration to a lower concentration.

Front 4

If alcohol inhibits ADH release, what is predicted?

Back 4

- typical amounts of normal concentrated urine
- large amounts of concentrated urine
* large amounts of dilute urine
- small amounts of concentrated urine

Front 5

A drug that inhibits chloride pumping out of the ascending limb of Loop of Henle would result in _____.

Back 5

- higher osmolarity inside the bottom of the nephron
- less salt in the descending limb
- less salt in the ascending limb
* less water removed from the descending limb

Front 6

A valuable nutrient such as glucose is reabsorbed from the proximal convoluted tubule into the blood through what process?

Back 6

- osmosis through aquaporins
* cotransport with sodium
- passive diffusion across the cell membrane
- primary active transport using an ATPase pump

Front 7

The descending limb of the loop of Henle is permeable to _____, and the thick portion of the ascending limb is permeable to _____.

Back 7

*water; Na+ and Cl-
-water; urea
-urea; water
-Na+ and Cl-; water

Front 8

Why is the surface area of the small intestine so high?

Back 8

-to better digest food
-to better eliminate waste
*to better absorb nutrients and water
-to better remove pathogens

Front 9

The chemical digestion of carbohydrates begins in the _____.

Back 9

-stomach
*mouth
-small intestine
-pancreas

Front 10

What is disrupted in individuals with people with Type 2 diabetes mellitus.

Back 10

-the pancreas producing insulin
*converting glucose to glycogen
-the pancreas producing glucagon
-converting glycogen to glucose

Front 11

Which of the following is true regarding blood glucose homeostasis?

Back 11

-All patients suffering from diabetes mellitus must take regular insulin injections.
*Insulin is released in response to increased blood glucose.
-Glucagon is released in response to increased blood glucose.
-The most important risk factor for Type 1 diabetes is obesity

Front 12

What would you predict if the curve of O2 saturation was steeper than normal?

Back 12

*a larger change in oxygen saturation of hemoglobin to a change in oxygen partial pressure
-a smaller change in oxygen saturation of hemoglobin to a change in oxygen partial pressure
-no change in oxygen saturation of hemoglobin to a change in oxygen partial pressure
-a constant change in oxygen saturation of hemoglobin to a change in oxygen partial pressure

Front 13

Which of the following does NOT correctly represent blood flow through the heart?

Back 13

-from the vena cava to the right atrium
*from the left ventricle to the aorta
-from the right ventricle to the left ventricle
-from the right atrium to the right ventricle

Front 14

A blood vessel that takes blood to the heart is a(n) _____.

Back 14

-lymphatic vessel
-artery
-capillary
*vein

Front 15

In terms of signaling, what is most significant about action potentials?

Back 15

*the frequency
-the number of phases
-the magnitude
-the number of partial action potentials

Front 16

A neuron sends a signal toward another neuron along its _____.

Back 16

-cell body
-dendrites
-ion channels
*axon

Front 17

At resting potential, the inside and outside of a neuron differ in _____.

Back 17

-sodium ion concentration
-charge
-potassium ion concentration
*All of the above

Front 18

During an action potential, why is there a positive feedback loop for the opening of sodium channels?

Back 18

*to rapidly depolarize the membrane
-to rapidly repolarize the membrane
-to quickly diminish the signal
-to trigger the closing of potassium channels

Front 19

During an Action Potential, where do potassium channels begin to open up?

Back 19

-at the hyperpolarization phase
*at the peak of the depolarization phase
-during the resting potential
-at the base of the depolarization phase

Front 20

The depolarization phase of an action potential is characterized by _____.

Back 20

-diffusion of sodium out of the cell
-active transport of sodium into the cell
*diffusion of sodium into the cell
-active transport of sodium out of the cell

Front 21

Action potentials are only propagated "downstream" (away from the cell body) because _____.

Back 21

-potassium channels upstream are refractory to action potentials
-sodium ions only move upstream along the inside of the cell membrane
*sodium channels upstream are refractory to action potentials
-sodium ions only move downstream along the inside of the cell membrane

Front 22

Neurotransmitters are released from neurons in response to the increase in intracellular concentration of what ion?

Back 22

-chloride
-potassium
*calcium
-sodium

Front 23

Which of the following is most likely to result in an action potential at a postsynaptic neuron?

Back 23

-few EPSPs and few IPSPs
-many EPSPs and many IPSPs
-few EPSPs and many IPSPs
*many EPSPs and few IPSPs

Front 24

The sympathetic nervous system would fall under the _____.

Back 24

*autonomic nervous system
-afferent division
-somatic nervous system
-the parasympathetic nervous system

Front 25

Which of the following types of sensory receptors would sense changes in pressure?

Back 25

-electroreceptors
*mechanoreceptors
-photoreceptors
-nociceptors

Front 26

Depolarization of hair cells in the mammalian ear results from increases in intracellular concentrations of what ion?

Back 26

-calcium
*potassium
-sodium
-chloride

Front 27

The sour taste of a grapefruit results from the binding of which of the following to chemoreceptors on the tongue?

Back 27

-sodium ions
*hydrogen ions
-glutamate
-glucose molecules

Front 28

What would occur if the uptake of calcium ions was blocked in the sarcoplasmic reticulum?

Back 28

-sustained muscle relaxation
-quicker repolarization of cell membrane
*sustained muscle contraction
-blocked reuptake of acetylcholine

Front 29

Which of the following structures shortens when a muscle contracts?

Back 29

*sarcomeres
-Z disk
-thick filaments
-thin filaments

Front 30

A muscle is contracted when which of the following occurs?

Back 30

-Troponin binds to myosin.
-Calcium levels in the muscle cell are low.
*Calcium binds to troponin.
-Troponin and tropomyosin block the myosin binding site on actin.

Front 31

Which of the following is the neurotransmitter released at the neuromuscular junction?

Back 31

-norepinephrine
*acetylcholine
-serotonin
-myosin

Front 32

What will occur if acetylcholine is not released from the neuromuscular junction?

Back 32

-binding of myosin to actin
-nothing, acetylcholine is only present in neurons
-sustained muscle contraction
*paralysis

Front 33

Negative feedback is defined as _____.

Back 33

-stimulation of hormone release by another hormone
*the product of a process inhibits its production
-the product of a process stimulates its production
-inhibition of hormone release by another hormone

Front 34

The main hormone released in response to short-term stress is _____, and to long-term stress is _____.

Back 34

-epinephrine; leptin
-leptin; cortisol
*epinephrine; cortisol
-cortisol; epinephrine

Front 35

Which of the following is an accurate pathway of hormonal release?

Back 35

-hypothalamus, CNS, anterior pituitary
-anterior pituitary, CNS, hypothalamus
-CNS, anterior pituitary, hypothalamus
*CNS, hypothalamus, anterior pituitary

Front 36

What accounts for the fact that the hormone estrogen only affects the uterus, hypothalamus, and mammary glands?

Back 36

-Only the uterus, hypothalamus, and mammary glands have estrogen hormone response elements.
-Estrogen only reaches the uterus, hypothalamus, and mammary glands.
*Only the uterus, hypothalamus, and mammary glands have estrogen receptors.
-Estrogen receptors are intracellular.

Front 37

The second messenger in liver cells stimulated by epinephrine is _____.

Back 37

*cAMP
-glucose
-adenyl cyclase
-phosphorylase

Front 38

How does testosterone release differ from cortisol release?

Back 38

-The signal for release of testosterone does not originate in the brain.
-Only testosterone is triggered by pituitary hormones.
-Instead of the hypothalamus, the thalamus releases the control hormone.
*Only testosterone is triggered by FSH.

Front 39

What would occur if estradiol levels were kept low throughout a menstrual cycle?

Back 39

*Ovulation would not occur.
-Ovulation would occur late in the cycle.
-Progesterone levels will spike.
-Ovulation would occur early in the cycle

Front 40

What would occur if follicle stimulating hormone levels were kept low throughout a menstrual cycle?

Back 40

-Progesterone would be maintained at a high level.
*No Estrogen (estradiol) would be produced.
-Estrogen would be maintained at a high level.
-The lining of the uterus would remain thickened

Front 41

Release of follicle-stimulating hormone (FSH) is stimulated by which of the following hormones?

Back 41

-progesterone
-testosterone
-luteinizing hormone (LH)
*gonadotropin-releasing hormone (GnRH)

Front 42

Ovulation is directly triggered by a surge in which of the following hormones?

Back 42

*luteinizing hormone (LH)
-follicle-stimulating hormone (FSH)
-progesterone
-estrogen

Front 43

How does a birth control pill operate to prevent fertilization?

Back 43

-It blocks progesterone receptors.
-Sperm is killed via toxin.
-It delivers continuous luteinizing hormone.
*It delivers continuous progesterone

Front 44

Which of the following is most accurate regarding blood vessels leading to a fresh wound?

Back 44

-Vessels are constricted both near and farther from the wound.
*Vessels are constricted near the wound and dilated farther away.
-Vessels are dilated near the wound and constricted farther away.
-Vessels are dilated both near and farther from the wound.

Front 45

Which of the following is the most important barrier to pathogen entry?

Back 45

-the mucous coat
-the waxy secretions
-the secretion of lysozyme
*the skin

Front 46

What is the difference between a B-cell receptor and an antibody?

Back 46

-Only B-cell receptors are considered immunoglobulins.
*Antibodies lack a transmembrane domain.
-B-cell receptors only bind to antigens that are modified by other cells.
-Antibodies are recognized by B-cell receptors

Front 47

The acquired response differs from the innate response based on which of the following attributes?

Back 47

-recognition of foreign cells
*specificity of the response
-lysis of bacterial pathogens
-induction of the inflammatory response

Front 48

What is responsible for the activation of lymphocytes?

Back 48

*encountering the specific antigens to which they are programmed to respond
-antigen binding to pattern recognition receptors
-interaction with T-helper cells
-cytokines

Front 49

B cell receptors are most similar to which of the following proteins?

Back 49

-pattern recognition receptors
-T cell receptor
-major histocompatibility protein (MHC)
*antibodies

Front 50

B cells and T cells have variable receptors that allow them to recognize virtually any epitope. What is responsible for this diversity?

Back 50

-alternatively spliced transcripts
-posttranslational modification of protein
-expression of different receptor genes
*gene recombination

Front 51

Which of the following will specifically lyse cells infected with viruses or other intracellular pathogens?

Back 51

-neutrophils
-B cells
*CD8+ T cells
-CD4+ T cells

Front 52

Antigen presenting cells use _____ to activate CD4+ T cells and _____ to activate CD8+ T cells.

Back 52

*class II MHC proteins; class I MHC proteins
-cytokines; class II MHC proteins
-class I MHC proteins; cytokines
-class I MH proteins; class II MHC proteins

Front 53

Which of the following best represents the humoral immune response?

Back 53

-activation of clotting factors
-secretion of chemokines
*production of antibodies
-activation of cytotoxic T cells

Front 54

Osmosis is the movement of __________
while diffusion is the movement of _____.

Back 54

*water; solutes
-water; water
-solutes; water
-solutes; solutes

Front 55

At what point is energy used to create the osmotic gradient found in the Loop of Henle?

Back 55

*Na+ and Cl- pumps of the thick ascending limb
-Osmosis of water in the descending limb
-Facilitated diffusion of Na+ and Cl- in the thin ascending limb
-None of the above
-All of the above

Front 56

What powers the co-transport of HCO3
- and Cl- ?

Back 56

-The proton pump
-The chloride channel
-The high concentration of protons produced by the dissociation of H2CO3
*The high concentration of HCO3- produced by the dissociation of H2CO3

Front 57

Glucose is absorbed due to the presence of:

Back 57

*An electrochemical gradient created by the Na/K pump
-An active transport molecule that pumps glucose
-Passive transport of glucose from the lumen into epithelial cells

Front 58

How does cooperative binding affect the rate of O2 binding to hemoglobin?

Back 58

-Each hemoglobin protein can bind a single O2 molecule; once that O2 binds, the next will bind another hemoglobin protein more easily.
-Each hemoglobin protein can bind four O2 molecules; once all four are bound, the next hemoglobin protein will bind its O2 more easily.
*Each hemoglobin protein can bind four O2
molecules; once one O2 binds that protein, the next will bind the same hemoglobin protein more easily

Front 59

Which of the following will have
a higher rate of diffusion?

Back 59

-a large respiratory surface that is at least 100 cells thick
*a large respiratory surface that is one to two cells thick
-a small respiratory surface that is at least 100 cells thick
-a small respiratory surface that is one to two cells thick

Front 60

During depolarization of the membrane, _____.

Back 60

-the membrane potential changes from neutral charge to a positive charge
-the membrane potential changes from highly positive to neutral
-the membrane potential changes from highly positive to highly negative
*the membrane potential changes from highly negative to positive

Front 61

Ligand-gated channels move ions via:

Back 61

*Facilitated Diffusion
-Diffusion
-Active Transport
-Osmosis

Front 62

Neurons communicate by:

Back 62

-Releasing neurotransmitters into neighboring neurons.
-Releasing sodium ions that physically move from one neuron to the next.
*Releasing neurotransmitters that trigger action potentials to spread down the length of the neighboring neuron.
-Releasing neurotransmitters that trigger sodium to rush down the length of the neighboring neuron.

Front 63

Which of the following are examples of active transport?

Back 63

-Acetylcholine Receptor in muscle cell membrane
-Calcium Voltage Gated Channel in sarcoplasmic reticulum
*Calcium pump in sarcoplasmic reticulum
-Potassium channels in hair cells
-All of the above

Front 64

Hormones work to:

Back 64

-maintain homeostasis.
-increase blood glucose levels when they are low.
-decrease blood glucose levels when they are high.
-None of the above.
*All of the above.

Front 65

Why can steroids cross the phospholipid membrane?

Back 65

-There are specific channels in the phospholipid membrane for steroid hormones.
*Steroid hormones are lipid-based molecules and therefore can move across the lipid bilayer.
-Steroids are actively transported against their concentration gradient into the cell.
-Steroids follow water into the cell.

Front 66

A hormone will act to _____.

Back 66

-increase the rate of transcription by binding an
intracellular receptor and activating gene expression
-change cellular activity of the target cell
-None of the above.
*All of the above.

Front 67

Which of these is a true statement about hormonal control of the menstrual cycle?

Back 67

-LH is inhibited during the entire cycle by negative
feedback of estradiol.
-Day 0 is marked by a spike of both LH and FSH.
*When estrogen levels are low, they inhibit LH through negative feedback; when they are high, they exert positive feedback on LH.
-When progesterone levels are high, they exert positive feedback on LH and FSH.

Front 68

Antigens are ________________, whereas antibodies are _____.

Back 68

*present on the foreign molecule; produced in response to a specific foreign molecule
-produced in response to a foreign molecule; the functional component of the immune system
-present on the foreign molecule; also present on a foreign molecule
-none of the above

Front 69

What is the function of B cells?

Back 69

-Activate T cells cells
*Secrete antibodies
-Kill infected host cells
-All of the above