Archive for October 2017

Solutions that contain buffers tend to resist pH changes because buffers

Naim 00:10

Solutions that contain buffers tend to resist pH changes because buffers



a. are bases.
b. change from ionic to nonionic in solution.
c. change from nonionic to ionic in response to changes in pH and release or absorb H+.
d. are weak acids or bases.
e. are ionic polar molecules that add or absorb H+ in solutions.




Answer: C

Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate ions. When this happens, the pH of the blood

Naim 00:09

Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate ions. When this happens, the pH of the blood



a. becomes basic.
b. becomes acidic.
c. does not change.
d. is reversible.
e. ionizes.




Answer: C

The optimum pH for growing strawberries is 6.5, whereas the optimum pH for growing blueberries is 4.5. Therefore, the number of hydrogen ions needed to grow strawberries is _______ times the number needed for blueberries.

Naim 00:09

The optimum pH for growing strawberries is 6.5, whereas the optimum pH for growing blueberries is 4.5. Therefore, the number of hydrogen ions needed to grow strawberries is _______ times the number needed for blueberries.




a. 2
b. 10
c. 100
d. 1,000
e. 1,000,000



Answer: E

The notation [H+] refers to the

Naim 00:09

The notation [H+] refers to the




a. number of H+ ions present in a solution.
b. number of protons in an H+ ion.
c. charge of an H+ ion.
d. concentration of H+ ions in moles per liter.
e. chemical reactivity of H+ ions.

Answer: D

The more acidic of two solutions has

Naim 00:08

The more acidic of two solutions has




a. more hydroxyl ions per liter.
b. more hydrogen acceptors per liter.
c. more H+ ions per liter.
d. a higher pH.
e. None of the above



Answer: C

A substance with a pH of 6.0 contains

Naim 00:08

A substance with a pH of 6.0 contains



a. 106 hydrogen ions.
b. 610 hydrogen ions.
c. 610 moles of hydrogen ions.
d. more OH- than H+.
e. 10-6 moles of hydrogen ions.



Answer: E

A basic solution contains

Naim 00:08

A basic solution contains




a. more OH- ions than H+ ions.
b. more H+ ions than OH- ions.
c. the same number of OH- ions and H+ ions.
d. no OH- ions.
e. None of the above


Answer: A

How would you make 100 ml of an aqueous solution with a 0.25 M concentration of a compound that has a molecular weight of 200 daltons?

Naim 00:07

How would you make 100 ml of an aqueous solution with a 0.25 M concentration of a compound that has a molecular weight of 200 daltons?




a. Add 0.25 grams of the compound to 100 ml of water.
b. Add 250 grams of the compound to 100 ml of water.
c. Take 250 grams of the compound and add water until the volume equals 100 ml.
d. Take 50 grams of the compound and add water until the volume equals 100 ml.
e. Take 5 grams of the compound and add water until the volume equals 100 ml.



Answer: E

To determine the number of molecules in a teaspoon of sugar you have to know

Naim 00:07

To determine the number of molecules in a teaspoon of sugar you have to know




a. the density of the sugar.
b. the weight of the sugar.
c. the molecular weight of the sugar.
d. Avogadro's number.
e. the weight and molecular weight of the sugar, and Avogadro's number.



Answer: E

The difference between an acid and a base is that an acid _______, whereas a base _______.

Naim 00:07

The difference between an acid and a base is that an acid _______, whereas a base _______.



a. undergoes a reversible reaction; does not
b. releases OH- ions in solution; accepts OH- ions
c. releases H+ ions in solution; releases OH- ions
d. releases OH- ions in solution; releases H+ ions
e. releases H+ ions in solution; accepts H+ ions




Answer: E

Ice is used in beverages primarily because

Naim 00:05

Ice is used in beverages primarily because



a. it is composed only of water.
b. it floats.
c. it dilutes the taste.
d. people like to chew it.
e. it absorbs a lot of heat when it melts.




Answer: E

Ice floats because

Naim 00:05

Ice floats because




a. the crystal takes up more space than the liquid.
b. substances expand when cooled.
c. heat is released and heat makes water expand.
d. hydrogen bonds must break.
e. heat is absorbed.


Answer: A

Which characteristic of water contributes to the relatively constant temperatures of the oceans?

Naim 00:05

Which characteristic of water contributes to the relatively constant temperatures of the oceans?



a. Water ionizes only slightly.
b. It takes a small amount of heat energy to raise the temperature of water.
c. Water can contain large amounts of salt.
d. Water has the ability to ionize readily.
e. It takes a large amount of heat energy to raise the temperature of water.




Answer: E

Sweating is a useful cooling device for humans because water

Naim 00:04

Sweating is a useful cooling device for humans because water



a. takes up a great deal of heat in changing from its liquid state to its gaseous state.
b. takes up a great deal of heat in changing from its solid state to its liquid state.
c. can exist in three states at temperatures common on Earth.
d. is an outstanding solvent.
e. ionizes readily.




Answer: A

Two characteristics of water make it different from most other compounds: Its solid state is _______ its liquid state and it takes up _______ heat to change to its gaseous state.

Naim 00:04

Two characteristics of water make it different from most other compounds: Its solid state is _______ its liquid state and it takes up _______ heat to change to its gaseous state.



a. less dense than; large amounts of
b. more dense than; small amounts of
c. less dense than; small amounts of
d. more dense than; large amounts of
e. just as dense as; no



Answer: A

Which of the following correctly states an unusual property of water?

Naim 00:04

Which of the following correctly states an unusual property of water?



a. Water will not react with other atoms.
b. Water's solid state is denser than its liquid state.
c. Energy is not required to change water from a solid to a liquid.
d. Little heat energy is needed to raise the temperature of water.
e. The hydrogen bonds between water molecules continually form and break.




Answer: E

A van der Waals interaction is an attraction between

Naim 00:03

A van der Waals interaction is an attraction between




a. variations in electron distributions in two adjacent nonpolar molecules.
b. the electrons of one molecule and the nucleus of the same molecule.
c. the electrons of one molecule and the electrons of a nearby molecule.
d. nonpolar molecules, due to the exclusion of water.
e. nonpolar molecules, because they are surrounded by water molecules.




Answer: A

Hydrogen bonds

Naim 00:02

Hydrogen bonds




a. form between two hydrogen atoms.
b. form only between hydrogen and oxygen atoms within a molecule.
c. form between a strong electronegative atom and hydrogen.
d. involve a transfer of electrons.
e. are the strongest bonds because of their length.


Answer: C

Ionic bonds are

Naim 00:02

Ionic bonds are




a. attractions between oppositely charged ions.
b. the result of electron sharing.
c. the strongest of the chemical bonds.
d. caused by partial electrical charges.
e. dependent upon hydrophobic interactions.


Answer: A

When magnesium (Mg) bonds with another element, you would expect that it would

Naim 00:01

When magnesium (Mg) bonds with another element, you would expect that it would




a. gain two electrons from the other element.
b. share four electrons with the other element.
c. lose two electrons to the other element.
d. form a hydrogen bond.
e. gain six electrons from the other element.



Answer: C

What determines if a molecule is polar, nonpolar, or ionic?

Naim 00:00

What determines if a molecule is polar, nonpolar, or ionic?



a. The number of protons
b. The bond distances
c. The differences in the electronegativities of the atoms
d. The ionic charges
e. The distance of the electrons from the nucleus



Answer: C

Which of the following is the correct order (in decreasing order) for the relative strengths of chemical bonds?

Naim 23:59

Which of the following is the correct order (in decreasing order) for the relative strengths of chemical bonds?





a. Covalent, ionic, hydrogen, van der Waals forces
b. Ionic, covalent, hydrogen, van der Waals forces
c. van der Waals forces, covalent, ionic, hydrogen
d. Hydrogen, covalent, van der Waals forces, ionic
e. Ionic, covalent, van der Waals forces, hydrogen


Answer: A

Which of the following statements about the difference between ionic bonds and covalent bonds is true?

Naim 23:59

Which of the following statements about the difference between ionic bonds and covalent bonds is true?



a. An ionic bond is stronger.
b. Electron sharing is more equal in the covalent bond.
c. An ionic bond occurs more often in aqueous solutions.
d. An ionic bond occurs only in acids.
e. A covalent bond occurs only in nonpolar molecules.




Answer: B

Nitrogen-14 and nitrogen-15 are isotopes. Nitrogen-15 is used to determine protein structure. Which of the following is true?

Naim 23:58

Nitrogen-14 and nitrogen-15 are isotopes. Nitrogen-15 is used to determine protein structure. Which of the following is true?




a. Nitrogen-15 has more protons than nitrogen-14.
b. Nitrogen-15 has more neutrons than nitrogen-14.
c. Nitrogen-15 has more electrons than nitrogen-14.
d. Nitrogen-15 has an electronic configuration that is different from that of nitrogen-14.
e. Nitrogen-15 has an equal number of protons and neutrons.




Answer: B

Carbon-12 is the most abundant isotope of carbon on Earth. Carbon-13 makes up about 1 percent of Earth's carbon atoms, and is useful for radioimaging. Which of the following is true?

Naim 23:58

Carbon-12 is the most abundant isotope of carbon on Earth. Carbon-13 makes up about 1 percent of Earth's carbon atoms, and is useful for radioimaging. Which of the following is true?




a. Carbon-13 has more protons than carbon-12.
b. Carbon-13 has more neutrons than carbon-12.
c. Carbon-13 has more electrons than carbon-12.
d. Carbon-13 has an electronic configuration that is different from that of carbon-12.
e. Carbon-13 has an equal number of protons and neutrons.



Answer: B

An atom with _______ has an atomic mass of 14.

Naim 23:57

An atom with _______ has an atomic mass of 14.



a. 14 neutrons
b. 14 electrons
c. 7 neutrons and 7 electrons
d. 7 protons and 7 electrons
e. 6 protons and 8 neutrons



Answer: E

Why is the atomic weight of hydrogen 1.008 and not exactly its mass number, 1.000?

Naim 23:56

Why is the atomic weight of hydrogen 1.008 and not exactly its mass number, 1.000?




a. Atomic weight does not take into account the weight of rare isotopes of an element.
b. Atomic weight is the average of the mass numbers of a representative sample of the element, including all its isotopes.
c. The atomic weight includes the weight of the electrons.
d. The atomic weight does not include the weight of the protons.
e. The mass number of an element is always lower than its atomic weight.




Answer: B

An element has a weight of 131.3. The reason the number is not a whole number is that

Naim 23:56

An element has a weight of 131.3. The reason the number is not a whole number is that




a. the atomic weight includes the weight of electrons.
b. atomic weight is the average of the mass numbers of all the element's isotopes.
c. the neutrons do not have a single unit weight.
d. the atomic weight does not include the weight of protons.
e. the number of electrons may vary.


Answer: B

The four elements most common in organisms are

Naim 23:55

The four elements most common in organisms are




a. calcium, iron, hydrogen, and oxygen.
b. water, carbon, hydrogen, and oxygen.
c. carbon, oxygen, hydrogen, and nitrogen.
d. nitrogen, carbon, iron, and hydrogen.
e. phosphorus, water, carbon, and oxygen.


Answer: C

An atom that is neutrally charged contains

Naim 23:53

An atom that is neutrally charged contains




a. only neutrons.
b. the same number of neutrons and electrons.
c. the same number of neutrons and protons.
d. the same number of protons and electrons.
e. no charged particles.




Answer: D

Which of the following statements about atoms is true?

Naim 23:52

Which of the following statements about atoms is true?



a. The negative charge of an electron is larger than the positive charge of a proton. This is the reason that there are usually more protons than electrons in an atom.
b. Neutrons add mass to an atom without influencing other properties.
c. When the number of protons equals the number of electrons, an atom has a neutral charge.




Answer: C

What is the difference between an atom and an element?

Naim 23:52

What is the difference between an atom and an element?



a. An atom is made of protons, electrons, and sometimes neutrons; an element is a substance composed of only one kind of atom.
b. An element is made of protons, electrons, and sometimes neutrons; an atom is a substance composed of only one kind of element.
c. An atom does not contain electrons, whereas an element does.
d. An atom contains protons and electrons, whereas an element contains protons, electrons, and neutrons.
e. None of the above



Answer: A

A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that

Naim 23:51

A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that



a. the person is suffering from a chronic disease such as diabetes.
b. the person has experienced prolonged exposure to radioactivity.
c. the person lives in a region where "heavy" water is consumed.
d. the person regularly uses a protein-rich hair conditioner.
e. the person eats a diet high in cholesterol-rich meat.


Answer: C

Protein phosphorylation is commonly involved with all of the following except

Naim 23:47

Protein phosphorylation is commonly involved with all of the following except




A) regulation of transcription by extracellular signaling molecules.
B) enzyme activation.
C) activation of G protein-coupled receptors.
D) activation of receptor tyrosine kinases.
E) activation of protein kinase molecules.


Answer: C

Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells?

Naim 23:47

Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells? 




A) Enzymatic activity was proportional to the amount of calcium added to a cell-free extract.
B) Receptor studies indicated that epinephrine was a ligand.
C) Glycogen breakdown was observed only when epinephrine was administered to intact cells.
D) Glycogen breakdown was observed when epinephrine and glycogen phosphorylase were combined.
E) Epinephrine was known to have different effects on different types of cells.





Answer: C

Apoptosis involves all but which of the following?

Naim 23:47

Apoptosis involves all but which of the following? 



A) fragmentation of the DNA
B) cell-signaling pathways
C) activation of cellular enzymes
D) lysis of the cell
E) digestion of cellular contents by scavenger cells



Answer: D

Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because

Naim 23:46

Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because 




A) only target cells retain the appropriate DNA segments.
B) intracellular receptors are present only in target cells.
C) most cells lack the Y chromosome required.
D) only target cells possess the cytosolic enzymes that transduce the testosterone.
E) only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor.




Answer: B

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane?

Naim 23:46

Binding of a signaling molecule to which type of receptor leads directly to a change in the distribution of ions on opposite sides of the membrane? 




A) receptor tyrosine kinase
B) G protein-coupled receptor
C) phosphorylated receptor tyrosine kinase dimer
D) ligand-gated ion channel
E) intracellular receptor


Answer: D

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because

Naim 23:45

Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because 



A) they are species specific.
B) they always lead to the same cellular response.
C) they amplify the original signal manyfold.
D) they counter the harmful effects of phosphatases.
E) the number of molecules used is small and fixed.



Answer: C

Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors that promote increased heart rate. Other drugs, called beta blockers, slow heart rate. Smooth muscle cells, however, have beta 2 receptors, which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma.

Naim 23:45

Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors that promote increased heart rate. Other drugs, called beta blockers, slow heart rate. Smooth muscle cells, however, have beta 2 receptors, which mediate muscle relaxation. Blockers of these effects are sometimes used to treat asthma. 


The description above illustrates which of the following?


A) Just because a drug acts on one type of receptor does not mean that it will act on another type.
B) Beta blockers can be used effectively on any type of muscle.
C) Beta adrenergic receptors must be in the cytosol if they are going to influence contraction and relaxation.
D) The chemical structures of the beta 1 and beta 2 receptors must have the same active sites.

Answer: A


The use of beta 2 antagonist drugs may be useful in asthma because they may 


A) increase constriction of the skeletal muscle of the chest wall.
B) increase heart rate and therefore allow the patient to get more oxygen circulated.
C) dilate the bronchioles by relaxing their smooth muscle.
D) override the beta blockers that the patient is already taking.
E) obstruct all G protein-mediated receptors.


Answer: C

Beta 2 antagonist drugs might also be used most effectively for which of the following? 



A) cardiac arrhythmias
B) increased gastric acid production
C) neuropathy of the extremities
D) increasing low blood pressure
E) decreasing peristalsis


Answer: D

Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone) for a receptor of interest is chemically linked to polystyrene beads. A solubilized preparation of membrane proteins is passed over a column containing these beads. Only the receptor binds to the beads.

Naim 23:44

Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone) for a receptor of interest is chemically linked to polystyrene beads. A solubilized preparation of membrane proteins is passed over a column containing these beads. Only the receptor binds to the beads. 


When an excess of the ligand (hormone) is poured through the column after the receptor binding step, what do you expect will occur?


A) The ligand will attach to those beads that have the receptor and remain on the column.
B) The ligand will cause the receptor to be displaced from the beads and eluted out.
C) The ligand will attach to the bead instead of the receptor.
D) The ligand will cause the bead to lose its affinity by changing shape.
E) The reaction will cause a pH change due to electron transfer.

Answer: B

This method of affinity chromatography would be expected to collect which of the following?



A) molecules of the hormone
B) molecules of purified receptor
C) G proteins
D) assorted membrane proteins
E) hormone-receptor complexes


Answer: B

A major group of G protein-coupled receptors contains seven transmembrane a helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others.

Naim 23:43

A major group of G protein-coupled receptors contains seven transmembrane a helices. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior face or on the cytosol face of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. 


Where would you expect to find the carboxyl end?


A) at the exterior surface
B) at the cytosol surface
C) connected with the loop at H5 and H6
D) between the membrane layers



Answer: B


The coupled G protein most likely interacts with this receptor 



A) at the NH3 end.
B) at the COO- end.
C) along the exterior margin.
D) along the interior margin.
E) at the loop between H5 and H6.


Answer: E


If you wish to design an experiment to block the G protein-coupled receptor interaction, the block would preferentially affect which of the following?



A) the exterior (cytoplasmic) end of the receptor
B) the cytosolic end of the receptor
C) the phospholipid's transmembrane domain
D) the amino acid sequence in the binding site for the G protein
E) the amino acids in the binding site for the transduction molecules


Answer: D

The human population's life expectancy has increased significantly but seems to have an upper limit. Which of the following might be described as an ecological consequence of passing that upper limit by regulating cell death?

Naim 23:42

The human population's life expectancy has increased significantly but seems to have an upper limit. Which of the following might be described as an ecological consequence of passing that upper limit by regulating cell death? 



A) an increase in the relative frequency of deaths from cancer
B) an increased need for gerontologists and other professionals to care for the elderly
C) an increase in the total population of humans on the planet
D) a decrease in the ratio of younger to older members of the population
E) a decrease in the birth rate

Answer: C

Where do apoptotic signals come from?

Naim 23:42

Where do apoptotic signals come from? 




A) the nucleus only
B) the ER only
C) ligand binding only
D) mitochondrial protein leakage only
E) all of the above



Answer: E

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling?

Naim 23:41

In research on aging (both cellular aging and organismal aging), it has been found that aged cells do not progress through the cell cycle as they had previously. Which of the following would provide evidence that this is related to cell signaling? 




A) Growth factor ligands do not bind as efficiently to receptors.
B) Their lower hormone concentrations elicit a lesser response.
C) cAMP levels change very frequently.
D) Enzymatic activity declines.
E) ATP production decreases.





Answer: A

In C. elegans, ced-9 prevents apoptosis in a normal cell in which of the following ways?

Naim 10:40

In C. elegans, ced-9 prevents apoptosis in a normal cell in which of the following ways? 



A) It prevents the caspase activity of ced-3 and ced-4.
B) Ced-9 remains inactive until it is signaled by ced-3 and other caspases.
C) Ced-9 cleaves to produce ced-3 and ced-4.
D) Ced-9 enters the nucleus and activates apoptotic genes.
E) Ced-9 prevents blebbing by its action on the cell membrane.



Answer: A

Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell?

Naim 10:40

Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell? 



A) Cell death would usually spread from one cell to the next via paracrine signals.
B) Lysosomal enzymes exiting the dying cell would damage surrounding cells.
C) Released cellular energy would interfere with the neighbors' energy budget.
D) Bits of membrane from the dying cell could merge with neighbors and bring in foreign receptors.
E) Neighboring cells would activate immunological responses.




Answer: B

If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result?

Naim 10:39

If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of the following is most likely to result? 



A) neurodegeneration
B) activation of a developmental pathway found in the worm but not in humans
C) a form of cancer in which there is insufficient apoptosis
D) webbing of fingers or toes
E) excess skin exfoliation




Answer: C

Which of the following describes the events of apoptosis?

Naim 10:39

Which of the following describes the events of apoptosis? 



A) The cell dies, it is lysed, its organelles are phagocytized, and its contents are recycled.
B) Its DNA and organelles become fragmented, it dies, and it is phagocytized.
C) The cell dies and the presence of its fragmented contents stimulates nearby cells to divide.
D) Its DNA and organelles are fragmented, the cell shrinks and forms blebs, and the cell self-digests.
E) Its nucleus and organelles are lysed, then the cell enlarges and bursts.




Answer: D

Why has C. elegans proven to be a useful model for understanding apoptosis?

Naim 10:39

Why has C. elegans proven to be a useful model for understanding apoptosis? 




A) The animal has as many genes as complex organisms, but finding those responsible is easier than in a more complex organism.
B) The nematode undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development.
C) This plant has a long-studied aging mechanism that has made understanding its death just a last stage.
D) While the organism ages, its cells die progressively until the whole organism is dead.
E) All of its genes are constantly being expressed so all of its proteins are available from each cell.




Answer: B

GTPase activity is involved in the regulation of signal transduction because it

Naim 10:39

GTPase activity is involved in the regulation of signal transduction because it 




A) increases the available concentration of phosphate.
B) decreases the amount of G protein in the membrane.
C) hydrolyzes GTP binding to G protein.
D) converts cGMP to GTP.
E) phosphorylates protein kinases.




Answer: C

The termination phase of cell signaling requires which of the following?

Naim 10:38

The termination phase of cell signaling requires which of the following? 



A) removal of the receptor
B) activation of a different set of relay molecules
C) converting ATP to camp
D) incompatibility of the binding of the signal molecule to the receptor
E) apoptosis



Answer: D

What are scaffolding proteins?

Naim 10:38

What are scaffolding proteins? 


A) ladderlike proteins that allow receptor-ligand complexes to climb through cells from one position to another
B) microtubular protein arrays that allow lipid-soluble hormones to get from the cell membrane to the nuclear pores
C) large molecules to which several relay proteins attach to facilitate cascade effects
D) relay proteins that orient receptors and their ligands in appropriate directions to facilitate their complexing
E) proteins that can reach into the nucleus of a cell to affect transcription




Answer: C

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects?

Naim 10:38

At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations of estrogens and other steroid hormones. How can one hormone, such as estrogen, mediate so many effects? 




A) Estrogen is produced in very large concentration and therefore diffuses widely.
B) Estrogen has specific receptors inside several cell types, but each cell responds in the same way to its binding.
C) Estrogen is kept away from the surface of any cells not able to bind it at the surface.
D) Estrogen binds to specific receptors inside many kinds of cells, each of which have different responses to its binding.
E) The subcomponents of estrogen, when metabolized, can influence cell response.




Answer: D

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?

Naim 10:38

A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following? 



A) lower cytoplasmic levels of cAMP
B) an increase in receptor tyrosine kinase activity
C) a decrease in transcriptional activity of certain genes
D) an increase in cytosolic calcium concentration
E) a decrease in G protein activity



Answer: C

In which of the following ways could signal transduction most probably be explored in research to treat cancer?

Naim 10:37

In which of the following ways could signal transduction most probably be explored in research to treat cancer? 




A) removal of serine/threonine phosphate acceptors from transduction pathways in colon pre-cancerous growths
B) alteration of protein kinases in cell cycle regulation in order to slow cancer growth
C) increase in calcium ion uptake into the cytoplasm in order to modulate the effects of environmental carcinogens
D) expansion of the role of transduction inhibitors in the cells before they give rise to cancer
E) increase in the concentration of phosphodiesterases in order to produce more AMP


Answer: B

What explains the increased concentration of Ca?? in the ER?

Naim 10:37

What explains the increased concentration of Ca?? in the ER? 



A) Calcium ions are actively imported from the cytoplasm into the ER.
B) Calcium concentration is kept low in the cytoplasm because of its high usage level.
C) Calcium cannot enter the plasma membrane through ion channels.
D) Calcium levels in the blood or other body fluids are extremely low.
E) The Ca ions are recycled from other molecules in the ER.



Answer: A

The function of phosphatases in signal transduction is best described as to

Naim 10:37

The function of phosphatases in signal transduction is best described as to 



A) move the phosphate group of the transduction pathway to the next molecule of a series.
B) prevent a protein kinase from being reused when there is another extracellular signal.
C) amplify the transduction signal so it affects multiple transducers.
D) amplify the second messengers such as cAMP.
E) inactivate protein kinases and turn off the signal transduction.




Answer: E

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?

Naim 10:37

Which of the following is the best explanation for the fact that most transduction pathways have multiple steps? 



A) Most of the steps were already in place because they are steps in other pathways.
B) Multiple steps in a pathway require the least amount of ATP.
C) Multiple steps provide for greater possible amplification of a signal.
D) Each individual step can remove excess phosphate groups from the cytoplasm.
E) Each step can be activated by several G proteins simultaneously.



Answer: C

One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. Since cGMP is inhibited, the signal is prolonged. The original signal that is now inhibited would have

Naim 10:36

One inhibitor of cGMP is Viagra. It provides a signal that leads to dilation of blood vessels and increase of blood in the penis, facilitating erection. Since cGMP is inhibited, the signal is prolonged. The original signal that is now inhibited would have 



A) hydrolyzed cGMP to GMP.
B) hydrolyzed GTP to GDP.
C) phosphorylated GDP.
D) dephosphorylated cGMP.
E) removed GMP from the cell.




Answer: A

Which of the following is a correct association?

Naim 10:36

Which of the following is a correct association? 



A) kinase activity and the addition of a tyrosine
B) phosphodiesterase activity and the removal of phosphate groups
C) GTPase activity and hydrolysis of GTP to GDP
D) phosphorylase activity and the catabolism of glucose
E) adenylyl cyclase activity and the conversion of cAMP to AMP



Answer: C

Which of the following statements is true of signal molecules?

Naim 10:36

Which of the following statements is true of signal molecules? 




A) When signal molecules first bind to receptor tyrosine kinases, the receptors phosphorylate a number of nearby molecules.
B) In response to some G protein-mediated signals, a special type of lipid molecule associated with the plasma membrane is cleaved to form IP3 and calcium.
C) In most cases, signal molecules interact with the cell at the plasma membrane and then enter the cell and eventually the nucleus.
D) Toxins such as those that cause botulism and cholera interfere with the ability of activated G proteins to hydrolyze GTP to GDP, resulting in phosphodiesterase activity in the absence of an appropriate signal molecule.
E) Protein kinase A activation is one possible result of signal molecules binding to G protein-coupled receptors.




Answer: E

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound

Naim 10:35

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound 



A) that mimics epinephrine and can bind to the epinephrine receptor.
B) that stimulates cAMP production in liver cells.
C) to stimulate G protein activity in liver cells.
D) that increases phosphodiesterase activity.
E) that does any of the above.




Answer: D

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound

Naim 10:35

If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound 



A) that activates epinephrine receptors.
B) that increases cAMP production in liver cells.
C) to block G protein activity in liver cells.
D) that increases phosphorylase activity.
E) that keeps sugar molecules from crossing the plasma membrane of liver cells.



Answer: C

An inhibitor of phosphodiesterase activity would have which of the following effects?

Naim 10:34

An inhibitor of phosphodiesterase activity would have which of the following effects? 



A) block the response of epinephrine
B) decrease the amount of cAMP in the cytoplasm
C) block the activation of G proteins in response to epinephrine binding to its receptor
D) prolong the effect of epinephrine by maintaining elevated cAMP levels in the cytoplasm
E) block the activation of protein kinase A




Answer: D

The toxin of Vibrio cholerae causes profuse diarrhea because it

Naim 10:34

The toxin of Vibrio cholerae causes profuse diarrhea because it 



A) modifies a G protein involved in regulating salt and water secretion.
B) decreases the cytosolic concentration of calcium ions, making the cells hypotonic.
C) binds with adenylyl cyclase and triggers the formation of cAMP.
D) signals IP3 to act as a second messenger for the release of calcium.
E) modifies calmodulin and activates a cascade of protein kinases.




Answer: A

Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2? concentration in its cytosol compared with the extracellular fluid?

Naim 10:33

Which of the following is the best explanation for the inability of a specific animal cell to reduce the Ca2? concentration in its cytosol compared with the extracellular fluid? 




A) blockage of the synaptic signal
B) loss of transcription factors
C) insufficient ATP levels in the cytoplasm
D) low oxygen concentration around the cell
E) low levels of protein kinase in the cell




Answer: C

Sutherland discovered that epinephrine signals

Naim 10:33

Sutherland discovered that epinephrine signals 




A) a decrease in levels of cAMP as a result of bypassing the plasma membrane.
B) lower blood glucose by binding to liver cells.
C) interactions with insulin inside muscle cells.
D) interactions directly with glycogen phosphorylase.
E) elevation of cytosolic concentrations of cyclic AMP.




Answer: E

In general, a signal transmitted via phosphorylation of a series of proteins

Naim 10:33

In general, a signal transmitted via phosphorylation of a series of proteins 




A) brings a conformational change to each protein.
B) requires binding of a hormone to a cytosol receptor.
C) cannot occur in yeasts because they lack protein phosphatases.
D) requires phosphorylase activity.
E) allows target cells to change their shape and therefore their activity.


Answer: A

Receptor tyrosine kinases (RTKs) are found at high levels on various cancer cells. A protein, Herceptin, has been found to bind to an RTK known as HER2. This information can now be utilized in breast cancer treatment if which of the following is true?

Naim 10:33

Receptor tyrosine kinases (RTKs) are found at high levels on various cancer cells. A protein, Herceptin, has been found to bind to an RTK known as HER2. This information can now be utilized in breast cancer treatment if which of the following is true? 




A) If Herceptin is found in the breast lymph nodes of the patient.
B) If HER2, administered by injection, is in sufficient concentration.
C) If the patient's cancer cells have detectable HER2.
D) If the patient's genome codes for the HER2 receptor.
E) If the patient's genome codes for the manufacture of Herceptin.



Answer: C

Since steroid receptors are located intracellularly, which of the following is true?

Naim 10:32

Since steroid receptors are located intracellularly, which of the following is true? 




A) The receptor molecules are themselves lipids or glycolipids.
B) The steroid/receptor complex can cross the nuclear membrane.
C) The unbound steroid receptors are quickly recycled by lysosomes.
D) The concentration of steroid receptors must be relatively high in most cells.
E) The receptor molecules are free to move in and out of most organelles.





Answer: B

Because most receptors are membrane proteins, which of the following is usually true?

Naim 10:32

Because most receptors are membrane proteins, which of the following is usually true? 




A) They lead to changes in intracellular ion concentration.
B) They open and close in response to protein signals.
C) They are only attached to one membrane surface: exterior or interior.
D) They preferentially bind with lipid or glycolipid signal molecules.
E) They change their conformation after binding with signal polypeptides.



Answer: E

One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this?

Naim 10:32

One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins. Which type does this? 



A) G protein-coupled receptors
B) ligand-gated ion channels
C) steroid receptors
D) receptor tyrosine kinases



Answer: D

Which of the following is true of transcription factors?

Naim 10:32

Which of the following is true of transcription factors? 



A) They regulate the synthesis of DNA in response to a signal.
B) They transcribe ATP into cAMP.
C) They initiate the epinephrine response in animal cells.
D) They control gene expression.
E) They regulate the synthesis of lipids in the cytoplasm.



Answer: D

Testosterone functions inside a cell by

Naim 10:31

Testosterone functions inside a cell by 



A) acting as a signal receptor that activates tyrosine kinases.
B) binding with a receptor protein that enters the nucleus and activates specific genes.
C) acting as a steroid signal receptor that activates ion channel proteins.
D) becoming a second messenger that inhibits adenylyl cyclase.
E) coordinating a phosphorylation cascade that increases spermatogenesis.


Answer: B

Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP?

Naim 10:31

Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP? 




A) It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
B) It could activate only the epinephrine system.
C) It would be able to carry out reception and transduction but would not be able to respond to a signal.
D) It would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane.
E) It would employ a transduction pathway directly from an external messenger.



Answer: A

Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to

Naim 10:31

Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to 




A) the active site of an allosteric enzyme that binds to a specific substrate.
B) tRNA specifying which amino acids are in a polypeptide.
C) a metabolic pathway operating within a specific organelle.
D) an enzyme having an optimum pH and temperature for activity.
E) an antibody in the immune system.



Answer: A

In an experiment to track the movement of growth factor molecules from secretion to the point of receptor binding in a particular species of mammal, a student found a 20-fold reduction in mm traveled when in the presence of an adrenal hormone. This is in part attributable to which of the following?

Naim 10:30

In an experiment to track the movement of growth factor molecules from secretion to the point of receptor binding in a particular species of mammal, a student found a 20-fold reduction in mm traveled when in the presence of an adrenal hormone. This is in part attributable to which of the following? 



A) The growth factor is a paracrine signal.
B) The growth factor depends on osmosis.
C) The mammal only carries growth factor through the lymph.
D) The growth factor is an exocrine signal.
E) The growth factor is an endocrine signal.



Answer: A

In which of the following ways do plant hormones differ from hormones in animals?

Naim 10:30

In which of the following ways do plant hormones differ from hormones in animals? 




A) Plant hormones interact primarily with intracellular receptors.
B) Plant hormones may travel in air or through vascular systems.
C) Animal hormones are found in much greater concentration.
D) Plant hormones are synthesized from two or more distinct molecules.
E) Animal hormones are primarily for mating and embryonic development.




Answer: B

In yeast signal transduction, the yeast cells

Naim 10:30

In yeast signal transduction, the yeast cells 



A) must physically and directly interact.
B) produce signal molecules that change themselves so they can interact with one another.
C) produce response molecules that diffuse to other yeast cells.
D) secrete molecules that result in response by other yeast cells.
E) mate, after which the new cells secrete hybrid signals.


Answer: D

In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

Naim 10:30

In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function? 



A) formation of mating complexes
B) secretion of apoptotic signals
C) aggregation of bacteria that can cause cavities
D) secretion of substances that inhibit foreign bacteria
E) digestion of unwanted parasite populations



Answer: C

Which of the following is characterized by a cell releasing a signal molecule into the environment, followed by a number of cells in the immediate vicinity responding?

Naim 10:29

Which of the following is characterized by a cell releasing a signal molecule into the environment, followed by a number of cells in the immediate vicinity responding? 




A) hormonal signaling
B) autocrine signaling
C) paracrine signaling
D) endocrine signaling
E) synaptic signaling




Answer: C

Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction?

Naim 10:29

Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction? 



A) Even in the simplest organisms, sexual reproduction required several coordinated responses by cells.
B) Multicellular eukaryotes required signals that were responded to by multiple organ systems.
C) Cells of several kinds of mating types needed to sort themselves to allow self-recognition.
D) Rooted plants required chemical diffusible signals that could travel throughout the organism.
E) Hormones required a mechanism for introducing changes in their target tissues.




Answer: A

What is most likely to happen to an animal's target cells that lack receptors for local regulators?

Naim 10:29

What is most likely to happen to an animal's target cells that lack receptors for local regulators? 




A) They might compensate by receiving nutrients via a factor.
B) They could develop normally in response to neurotransmitters instead.
C) They could divide but never reach full size.
D) They might not be able to multiply in response to growth factors from nearby cells.
E) Hormones would not be able to interact with target cells.



Answer: D

Using the yeast signal transduction pathways, both types of mating cells release the mating factors. These factors bind to specific receptors on the correct cells,

Naim 10:29

Using the yeast signal transduction pathways, both types of mating cells release the mating factors. These factors bind to specific receptors on the correct cells, 



A) which induce changes in the cells that lead to cell fusion.
B) which produce more of the a factor in a positive feedback.
C) then one cell nucleus binds the mating factors and produces a new nucleus in the opposite cell.
D) stimulating cell membrane disintegration, releasing the mating factors that lead to new yeast cells.
E) which in turn releases a growth factor that stimulates mitosis in both cells.




Answer: A

Eyebrow hairs are always shorter than hairs on your head because ________.

Naim 10:28

Eyebrow hairs are always shorter than hairs on your head because ________.




A) they grow much slower
B) eyebrow follicles are only active for a few months
C) the vascular supply of the eyebrow follicle is one-tenth that of the head hair follicle
D) hormones in the eyebrow follicle switch the growth off after it has reached a predetermined length



Answer: B

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous fluid loss?

Naim 10:27

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous fluid loss? 



A) by measuring urinary output and fluid intake
B) by observing the tissues that are usually moist
C) through blood analysis
D) by using the "rule of nines"





Answer: D

In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin?

Naim 10:27

In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin? 




A) It converts modified epidermal cholesterol to a vitamin D precursor important to calcium metabolism.
B) It aids in the transport of materials throughout the body.
C) The cells of the epidermis store glucose as glycogen for energy.
D) It absorbs vitamin C so that the skin will not be subject to diseases.



Answer: A

Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these glands in the human body?

Naim 10:26

Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these glands in the human body? 





A) in all body regions and buried deep in the dermis
B) beneath the flexure lines in the body
C) in the axillary and anogenital area
D) in the palms of the hands and soles of the feet




Answer: C

The composition of the secretions of the eccrine glands is ________.

Naim 10:26

The composition of the secretions of the eccrine glands is ________. 




A) primarily uric acid
B) 99% water, sodium chloride, trace amounts of wastes, and vitamin C
C) fatty substances, proteins, antibodies, and trace amounts of minerals and vitamins
D) metabolic wastes




Answer: B

Which of the following statements best describes what fingernails actually are?

Naim 10:26

Which of the following statements best describes what fingernails actually are? 



A) Fingernails are a modification of the epidermis.
B) Fingernails are derived from osseous tissue.
C) Fingernails are extensions of the carpal bones.
D) Fingernails are a separate tissue from the skin, formed from a different embryonic layer.




Answer: A

A Langerhans' cell is a ________.

Naim 10:25

A Langerhans' cell is a ________. 



A) specialized squamous epithelial cell
B) specialized phagocytic cell
C) specialized nerve cell
D) specialized melanocyte




Answer: B

Changes in the color of skin are often an indication of a homeostatic imbalance. Which of the following changes would suggest that a patient is suffering from Addison's disease?

Naim 10:25

Changes in the color of skin are often an indication of a homeostatic imbalance. Which of the following changes would suggest that a patient is suffering from Addison's disease? 





A) The skin takes on a bronze or metallic appearance.
B) Black-and-blue marks become evident for no apparent cause.
C) The skin appears to have an abnormal, yellowish tint.
D) It is impossible to suggest Addison's disease from an inspection of a person's skin.




Answer: A

Which of the following statements indicates the way in which the body's natural defenses protect the skin from the effects of UV damage?

Naim 10:25

Which of the following statements indicates the way in which the body's natural defenses protect the skin from the effects of UV damage? 



A) The skin is protected by the synthesis of three pigments that contribute to the skin's color.
B) Carotene, which accumulates in the stratum corneum and hypodermal adipose tissue, is synthesized in large amounts in the presence of sunlight.
C) The skin is protected by increasing the number of Langerhans' cells, which help to activate the immune system.
D) Prolonged exposure to the sun induces melanin dispersion, which in turn acts as a natural sunscreen.



Answer: D

The design of a person's epidermal ridges is determined by the manner in which the papillae rest upon the dermal ridges to produce the specific pattern known as handprints, footprints, and fingerprints. Which of the following statements is true regarding these prints or ridges?

Naim 10:24

The design of a person's epidermal ridges is determined by the manner in which the papillae rest upon the dermal ridges to produce the specific pattern known as handprints, footprints, and fingerprints. Which of the following statements is true regarding these prints or ridges? 



A) Every human being has the same pattern of ridges.
B) They are genetically determined, therefore unique to each person.
C) Because we are constantly shedding epithelial cells, these ridges are changing daily.
D) Identical twins do not have the same pattern of ridges.





Answer: B

Despite its apparent durability, the dermis is subject to tearing. How might a person know that the dermis has been stretched and/or torn?

Naim 10:24

Despite its apparent durability, the dermis is subject to tearing. How might a person know that the dermis has been stretched and/or torn? 



A) Because the pain is acute due to the large number of Meissner's corpuscles.
B) The appearance of visible, silvery-white scars is an indication of stretching of the dermis.
C) The blood vessels in the dermis rupture and the blood passes through the tissue, causing "black and blue marks."
D) The stretching causes the tension lines to disappear.




Answer: B

The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis?

Naim 10:24

The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis? 




A) goblet cells, parietal cells, and Kupffer cells
B) monocytes, reticulocytes, and osteocytes
C) fibroblasts, macrophages, and mast cells
D) osteoblasts, osteoclasts, and epithelial cells



Answer: C

Water loss through the epidermis could cause a serious threat to health and well-being. Which of the following protects us against excessive water loss through the skin?

Naim 10:23

Water loss through the epidermis could cause a serious threat to health and well-being. Which of the following protects us against excessive water loss through the skin? 




A) Lamellated granules of the cells of the stratum granulosum, a glycolipid that is secreted into extracellular spaces.
B) The size and shape of the cells that make up the stratum spinosum, as well as the thick bundles of intermediate filaments.
C) The dermis is the thickest portion of the skin and water cannot pass through it.
D) Fat associated with skin prevents water loss.


Answer: A

The integumentary system is protected by the action of cells that arise from bone marrow and migrate to the epidermis. Which of the following cells serve this function?

Naim 10:23

The integumentary system is protected by the action of cells that arise from bone marrow and migrate to the epidermis. Which of the following cells serve this function? 



A) cells found in the stratum spinosum
B) macrophages called Langerhans' cells
C) keratinocytes, because they are so versatile
D) Merkel cells





Answer: B

The epidermis consists of five layers of cells, each layer with a distinct role to play in the health, well-being, and functioning of the skin. Which of the following layers is responsible for cell division and replacement?

Naim 10:23

The epidermis consists of five layers of cells, each layer with a distinct role to play in the health, well-being, and functioning of the skin. Which of the following layers is responsible for cell division and replacement? 



A) stratum corneum
B) stratum granulosum
C) stratum basale
D) stratum lucidum




Answer: C

Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________.

Naim 10:23

Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________. 



A) provide the melanocyte with a protective shield against abrasion
B) accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer
C) maintain the appropriate pH in order for the melanocyte to synthesize melanin granules
D) maintain the appropriate temperature so the product of the melanocyte will not denature




Answer: B

Keratinocytes are an important epidermal cell because ________.

Naim 10:22

Keratinocytes are an important epidermal cell because ________. 



A) they produce a fibrous protein that gives the skin much of its protective properties
B) they are able to transform from living cells to plasma membranes and still function
C) they are able to reproduce sporadically as needed
D) they are a powerful defense against damaging UV rays



Answer: A

The epidermis is responsible for protecting the body against invasion of bacteria and other foreign agents primarily because it is composed of ________.

Naim 10:22

The epidermis is responsible for protecting the body against invasion of bacteria and other foreign agents primarily because it is composed of ________. 




A) stratified columnar epithelium
B) three layers of keratinized cells only
C) four different cell shapes found in five distinct layers, each cell shape with a special function
D) a tough layer of connective tissue



Answer: C

The reason the hypodermis acts as a shock absorber is that ________.

Naim 10:22

The reason the hypodermis acts as a shock absorber is that ________. 



A) it is located just below the epidermis and protects the dermis from shock
B) it has no delicate nerve endings and can therefore absorb more shock
C) the major part of its makeup is adipose, which serves as an effective shock absorber
D) the cells that make up the hypodermis secrete a protective mucus




Answer: C

Nutrients reach the surface of the skin (epidermis) through the process of ________.

Naim 10:22

Nutrients reach the surface of the skin (epidermis) through the process of ________. 




A) absorbing materials applied to the surface layer of the skin
B) utilizing the products of merocrine glands to nourish the epidermis
C) filtration
D) diffusing through the tissue fluid from blood vessels in the dermis


Answer: D

Vernix caseosa is a ________.

Naim 10:21

Vernix caseosa is a ________. 





A) substance contributing to acne during adolescence
B) whitish material produced by fetal sebaceous glands
C) coat of fine, downy hair on the heads of balding men
D) cheesy-looking sudoriferous secretion on the skin of newborns


Answer: B

The function of the root hair plexus is to ________.

Naim 10:21

The function of the root hair plexus is to ________. 




A) serve as a source for new epidermal cells for hair growth after the resting stage has passed
B) bind the hair root to the dermis
C) cause apocrine gland secretion into the hair follicle
D) allow the hair to assist in touch sensation


Answer: D

Although the integument is a covering, it is by no means simple, and some of its functions include ________.

Naim 10:21

Although the integument is a covering, it is by no means simple, and some of its functions include ________. 





A) the dermis providing the major mechanical barrier to chemicals, water, and other external substances
B) resident macrophage-like cells whose function is to ingest antigenic invaders and present them to the immune system
C) cooling the body by increasing the action of sebaceous glands during high-temperature conditions
D) epidermal blood vessels serving as a blood reservoir


Answer: B

Sudoriferous glands vary in distribution over the surface of the body. Which of the following is correct?

Naim 10:20

Sudoriferous glands vary in distribution over the surface of the body. Which of the following is correct? 



A) Eccrine are the most numerous, being found primarily in the axillary regions.
B) Apocrine glands are larger than eccrine, and empty secretions directly to the surface of the skin.
C) Ceruminous glands secrete cerumen, which is thought to deter insects.
D) Mammary glands are not considered a modified sweat gland.



Answer: C

Which statement correctly explains why hair appears the way it does?

Naim 10:20

Which statement correctly explains why hair appears the way it does? 



A) Kinky hair has flat, ribbonlike hair shafts.
B) Perfectly round hair shafts result in wavy hair.
C) Air bubbles in the hair shaft cause straight hair.
D) Gray hair is the result of hormonal action altering the chemical composition of melanin.



Answer: A

Melanocytes ________.

Naim 10:20

Melanocytes ________. 



A) are spidery-shaped cells in contact with cells in the stratum basale
B) are involved in the immune system
C) are involved with the nervous system
D) work their way up to the surface just like the keratinocytes




Answer: A

The dermis ________.

Naim 10:19

The dermis ________. 



A) is an avascular connective tissue layer
B) has two layers
C) lacks sensory corpuscles and glands
D) is where melanocytes are found



Answer: B

Select the most correct statement concerning skin cancer.

Naim 10:18

Select the most correct statement concerning skin cancer. 



A) Most tumors that arise on the skin are malignant.
B) Squamous cell carcinomas arise from the stratum corneum.
C) Basal cell carcinomas are the least common but most malignant.
D) Melanomas are rare but must be removed quickly to prevent them from metastasizing.



Answer: D

How do glucocorticoids enable the body to deal appropriately with stress?

Naim 06:36

How do glucocorticoids enable the body to deal appropriately with stress?



A) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure
B) by decreasing the heart rate, thus decreasing blood pressure
C) by stimulating the pancreas to release insulin
D) by blocking the neurotransmitters that prepare the body for the stress response



Answer: A

Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?

Naim 06:36

Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?



A) It causes positive feedback.
B) It does not require a second messenger to effect a response.
C) It is very specific in the cell type it targets.
D) It is a stimulant of cellular metabolism and targets all cells.



Answer: B

A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH), and for this reason he may be unable to father a child. Choose the correct statement to explain this problem.

Naim 06:35

A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH), and for this reason he may be unable to father a child. Choose the correct statement to explain this problem.



A) FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by males.
B) The physician is wronga hormone made in the adenohypophysis could not influence fertility.
C) FSH stimulates sperm production in the testes.
D) The man must be producing progesterone, which inhibits the synthesis of FSH.




Answer: C

In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________.

Naim 06:34

In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________.




A) the cell's sensitivity reaction
B) cellular affinity
C) up-regulation
D) a reaction to a stressor




Answer: C

Aldosterone ________.

Naim 06:34

Aldosterone ________.



A) is secreted by the neurohypophysis
B) functions to increase sodium reabsorption
C) presence increases potassium concentration in the blood
D) production is greatly influenced by ACTH




Answer: B

Which of the following is true about calcium homeostasis?

Naim 06:33

Which of the following is true about calcium homeostasis?




A) Increased calcitonin levels will cause increased blood calcium levels.
B) High calcium levels cause bone resorption.
C) Parathyroid hormone causes an increase in osteoblast activity.
D) Parathyroid hormone is the single most important regulator of calcium levels in the blood.



Answer: D

ACTH ________.

Naim 06:33

ACTH ________.



A) is secreted by the posterior pituitary
B) secretion is regulated by a hypothalamic secretion
C) causes the release of hormones from the adrenal medulla
D) is not a tropic hormone




Answer: B

Regulating hormones from the hypothalamus ________.

Naim 06:33

Regulating hormones from the hypothalamus ________.




A) enter venous circulation and travel to the heart, which pumps the hormone-containing blood to the pituitary
B) enter the hepatic portal system, which feeds the pituitary
C) travel by arteries to the pituitary
D) first enter into the hypophyseal portal system


Answer: D

Cellular responses to hormones that initiate second-messenger systems include ________.

Naim 06:33

Cellular responses to hormones that initiate second-messenger systems include ________.



A) possible activation of several different second-messenger systems
B) cyclic AMP phosphodiesterase formation of an active second messenger
C) formation of a specific protein kinase that acts on a series of extracellular intermediates
D) hormone binding to intracellular receptors




Answer: A

Which of the following would be associated with the action of steroids on cells?

Naim 06:32

Which of the following would be associated with the action of steroids on cells?



A) extracellular receptors with a specificity for only a single amino acid sequence on the hormone
B) an enzyme that catalyzes the formation of cyclic AMP
C) second-messenger systems
D) a hormone-receptor complex that interacts directly with the cell's DNA




Answer: D

Leptin is secreted by ________.

Naim 06:31

Leptin is secreted by ________.




A) lymphocytes
B) adipocytes
C) goblet cells
D) fibroblasts



Answer: B
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