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...
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
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...
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.
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...
Which of the following has the greatest concentration of hydrogen ions?
Which of the following has the greatest concentration of hydrogen ions?
a. Household ammonia at pH 11
b. Baking soda at pH 9
c. Human blood at pH...
The notation [H+] refers to the
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...
Acid rain is a serious environmental problem. A sample of rainwater collected in the Adirondack Mountains had an H+ concentration of 10-4 mol/L. The pH of this sample was
Acid rain is a serious environmental problem. A sample of rainwater collected in the Adirondack Mountains had an H+ concentration of 10-4 mol/L. The...
The more acidic of two solutions has
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...
A substance with a pH of 6.0 contains
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...
A 1.0 M solution of HCl has a pH of
A 1.0 M solution of HCl has a pH of
a. 1.0.
b. 7.0.
c. 14.0.
d. 11.2.
e. 14.
Answer:...
A basic solution contains
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....
Of the following compounds containing 1H, 12C, and 16O, the one with the greatest number of molecules in a sample with a mass of 2 grams would be
Of the following compounds containing 1H, 12C, and 16O, the one with the greatest number of molecules in a sample with a mass of 2 grams would be
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?
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...
To determine the number of molecules in a teaspoon of sugar you have to know
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...
The difference between an acid and a base is that an acid _______, whereas a base _______.
The difference between an acid and a base is that an acid _______, whereas a base _______.
a. undergoes a reversible reaction; does not
b. releases...
Which contains more molecules, a mole of hydrogen or a mole of carbon?
Which contains more molecules, a mole of hydrogen or a mole of carbon?
a. A mole of carbon
b. A mole of hydrogen
c. Both contain the same number...
H2SO4 can ionize to yield two H+ ions and one SO42- ion. H2SO4 is therefore
H2SO4 can ionize to yield two H+ ions and one SO42- ion. H2SO4 is therefore
a. molar.
b. a base.
c. a buffer.
d. a solution.
e. an acid.
Answer:...
When sodium hydroxide (NaOH) is added to water, it ionizes, releasing OH- and Na+ ions. The resulting solution is
When sodium hydroxide (NaOH) is added to water, it ionizes, releasing OH- and Na+ ions. The resulting solution is
a. acidic.
b. basic.
c. neutral.
d....
The molecular weight of water is 18.0154. One mole of water weighs _______ grams.
The molecular weight of water is 18.0154. One mole of water weighs _______ grams.
a. 9
b. 18
c. 20
d. 36.031
e. 6.023 × 1023
Answer:...
Surface tension and capillary action occur in water because it
Surface tension and capillary action occur in water because it
a. is wet.
b. is dense.
c. has hydrogen bonds.
d. is nonpolar.
e. has ionic bonds.
Answer:...
If you place a paper towel in a dish of water, the water will move up the towel by capillary action because water
If you place a paper towel in a dish of water, the water will move up the towel by capillary action because water
a. molecules ionize.
b. is a good...
Ice is used in beverages primarily because
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...
Ice floats because
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...
Which characteristic of water contributes to the relatively constant temperatures of the oceans?
Which characteristic of water contributes to the relatively constant temperatures of the oceans?
a. Water ionizes only slightly.
b. It takes a small...
When exposed to extreme heat, the human body relies on _______ to absorb excess calories of heat and maintain normal body temperature.
When exposed to extreme heat, the human body relies on _______ to absorb excess calories of heat and maintain normal body temperature.
a. evaporation
b....
Sweating is a useful cooling device for humans because water
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....
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.
Two characteristics of water make it different from most other compounds: Its solid state is _______ its liquid state and it takes up _______ heat to...
Which of the following correctly states an unusual property of water?
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...
In addition to covalent and ionic bonds, which of the following interactions are important in biological systems?
In addition to covalent and ionic bonds, which of the following interactions are important in biological systems?
a. van der Waals interactions
b....
A van der Waals interaction is an attraction between
A van der Waals interaction is an attraction between
a. variations in electron distributions in two adjacent nonpolar molecules.
b. the electrons...
The hydrogen bond between two water molecules arises because water is
The hydrogen bond between two water molecules arises because water is
a. polar.
b. nonpolar.
c. a liquid.
d. a small molecule.
e. hydrophobic.
Answer:...
Cholesterol is composed primarily of carbon and hydrogen atoms. Therefore, one would expect cholesterol to be
Cholesterol is composed primarily of carbon and hydrogen atoms. Therefore, one would expect cholesterol to be
a. insoluble in water.
b. a polar molecule.
c....
Hydrogen bonds
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...
Which of the following molecules is held together primarily by ionic bonds?
Which of the following molecules is held together primarily by ionic bonds?
a. H2O
b. C6H12O6
c. NaCl
d. H2
e. NH3
Answer: ...
Particles having a net negative charge are called
Particles having a net negative charge are called
a. electronegative.
b. cations.
c. anions.
d. acids.
e. bases.
Answer:...
Ionic bonds are
Ionic bonds are
a. attractions between oppositely charged ions.
b. the result of electron sharing.
c. the strongest of the chemical bonds.
d. caused...
When magnesium (Mg) bonds with another element, you would expect that it would
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...
All of the following are nonpolar except
All of the following are nonpolar except
a. O2.
b. N2.
c. CH4.
d. NaCl.
e. H2.
Answer:...
Chemical bonds formed by electrical attractions are
Chemical bonds formed by electrical attractions are
a. covalent bonds.
b. ionic bonds.
c. hydrogen bonds.
d. van der Waals forces.
e. Both b and...
A covalent bond is the sharing of _______ between atoms, whereas an ionic bond is the _______.
A covalent bond is the sharing of _______ between atoms, whereas an ionic bond is the _______.
a. neutrons; sharing of electrons
b. electrons; electric...
Two carbon atoms held together in a double covalent bond share _______ electron(s).
Two carbon atoms held together in a double covalent bond share _______ electron(s).
a. one
b. two
c. four
d. six
e. eight
Answer:...
Two atoms are held together in four covalent bonds because of forces between the
Two atoms are held together in four covalent bonds because of forces between the
a. electrons and protons.
b. electrons.
c. protons and neutrons.
d....
What determines if a molecule is polar, nonpolar, or ionic?
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...
Oxygen forms _______ covalent bond(s), carbon forms _______, and hydrogen forms _______.
Oxygen forms _______ covalent bond(s), carbon forms _______, and hydrogen forms _______.
a. one; four; one
b. four; four; four
c. two; four; none
d....
Which of the following atoms usually has the greatest number of covalent bonds with other atoms?
Which of the following atoms usually has the greatest number of covalent bonds with other atoms?
a. Carbon
b. Oxygen
c. Sulfur
d. Hydrogen
e. Nitrogen
Answer:...
A single covalent chemical bond represents the sharing of how many electrons?
A single covalent chemical bond represents the sharing of how many electrons?
a. One
b. Two
c. Three
d. Four
e. Six
Answer:...
Which of the following is the correct order (in decreasing order) for the relative strengths of chemical bonds?
Which of the following is the correct order (in decreasing order) for the relative strengths of chemical bonds?
a. Covalent, ionic, hydrogen, van...
In a hydrogen molecule, the two atoms are held together by
In a hydrogen molecule, the two atoms are held together by
a. hydrogen bonds.
b. a shared pair of electrons.
c. van der Waals forces.
d. ionic attractions.
e....
Which of the following statements about the difference between ionic bonds and covalent bonds is true?
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...
Which of the elements listed below does not follow the octet rule?
Which of the elements listed below does not follow the octet rule?
a. Sodium
b. Chlorine
c. Carbon
d. Hydrogen
e. Nitrogen
Answer:...
Which of the following elements is the most chemically reactive?
Which of the following elements is the most chemically reactive?
a. Hydrogen
b. Helium
c. Neon
d. Argon
e. They all have the same chemical reactivity.
Answer:...
Nitrogen-14 and nitrogen-15 are isotopes. Nitrogen-15 is used to determine protein structure. Which of the following is true?
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...
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?
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....
The atomic mass of an element is the same as the number of _______ in each atom.
The atomic mass of an element is the same as the number of _______ in each atom.
a. electrons
b. protons
c. neutrons
d. protons plus neutrons
e....
Phosphorus has an atomic number of 15 and an atomic weight of 30.974. From this information it can be determined that this element
Phosphorus has an atomic number of 15 and an atomic weight of 30.974. From this information it can be determined that this element
a. has isotopes.
b....
The ability of atoms to combine with other atoms is determined by
The ability of atoms to combine with other atoms is determined by
a. the atom's atomic weight.
b. the number and distribution of electrons.
c. the...
An atom with _______ has an atomic mass of 14.
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...
Hydrogen, deuterium, and tritium all have the same
Hydrogen, deuterium, and tritium all have the same
a. atomic weight.
b. atomic number.
c. mass.
d. density.
e. nuclear composition.
Answer:...
The mass number of an atom is determined primarily by the _______ it contains.
The mass number of an atom is determined primarily by the _______ it contains.
a. number of electrons
b. number of protons
c. sum of the number of...
Why is the atomic weight of hydrogen 1.008 and not exactly its mass number, 1.000?
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...
An element has a weight of 131.3. The reason the number is not a whole number is that
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...
Because atoms can have the same number of protons but a different number of neutrons, elements have
Because atoms can have the same number of protons but a different number of neutrons, elements have
a. isotopes.
b. more than one atomic mass listed...
3115P and 3215P have virtually identical chemical and biological properties because they have the same.
3115P and 3215P have virtually identical chemical and biological properties because they have the same.
a. half-life.
b. number of neutrons.
c. atomic...
Phosphorus has an atomic number of 15 and an atomic mass of 31. How many neutrons does phosphorus have?
Phosphorus has an atomic number of 15 and an atomic mass of 31. How many neutrons does phosphorus have?
a. 5
b. 16
c. 30
d. 31
e. 47
Answer:...
Which of the following pairs has similar chemical properties?
Which of the following pairs has similar chemical properties?
a. 1H and 22Na
b. 12C and 28Si
c. 16O and 8S
d. 12C and 14C
e. 8H and 2He
Answer:...
The four elements most common in organisms are
The four elements most common in organisms are
a. calcium, iron, hydrogen, and oxygen.
b. water, carbon, hydrogen, and oxygen.
c. carbon, oxygen,...
Which of the following elements is contained by all living things?
Which of the following elements is contained by all living things?
a. Nitrogen
b. Phosphorus
c. Sulfur
d. Carbon
e. All of the above
Answer:...
The atomic number of an element is the same as the number of _______ in each atom.
The atomic number of an element is the same as the number of _______ in each atom.
a. neutrons
b. protons plus electrons
c. protons
d. neutrons plus...
Compared to carbon, silicon has the same number of
Compared to carbon, silicon has the same number of
a. protons.
b. valence (outer-shell) electrons.
c. neutrons.
d. electrons.
e. Both a and c
Answer:...
The compounds that sulfur forms with hydrogen are most like the compounds found in which of the following?
The compounds that sulfur forms with hydrogen are most like the compounds found in which of the following?
a. CH4
b. NH3
c. H2O
d. NaCl
e. CaCl2
Answer:...
Which of the following has the same number of outer-shell (valence) electrons as oxygen has?
Which of the following has the same number of outer-shell (valence) electrons as oxygen has?
a. Sulfur
b. Nitrogen
c. Fluorine
d. Sodium
e. Calcium
Answer:...
The best reference source for the atomic number and mass number of elements is
The best reference source for the atomic number and mass number of elements is
a. a good chemistry text.
b. a dictionary.
c. the periodic table.
d....
The number of different elements found in the universe is closest to
The number of different elements found in the universe is closest to
a. 12.
b. 24.
c. 48.
d. 100.
e. 192.
Answer:...
An atom that is neutrally charged contains
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....
Which of the following statements about atoms is true?
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...
The number of protons in a neutral atom equals the number of
The number of protons in a neutral atom equals the number of
a. neutrons.
b. electrons.
c. electrons plus neutrons.
d. neutrons minus electrons.
e....
What is the difference between an atom and an element?
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...
Which component of an atom does not significantly add to its mass?
Which component of an atom does not significantly add to its mass?
a. Proton
b. Neutron
c. Electron
d. Both a and b
e. All of the above
Answer:...
The part of the atom that determines how the atom behaves chemically is the
The part of the atom that determines how the atom behaves chemically is the
a. proton.
b. electron.
c. neutron.
d. innermost shell.
e. nucleus.
Answer:...
A human hair is found to have a high ratio of 18O to 16O. From this information it can be assumed that
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...
Protein phosphorylation is commonly involved with all of the following except
Protein phosphorylation is commonly involved with all of the following except
A) regulation of transcription by extracellular signaling molecules.
B)...
Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells?
Which observation suggested to Sutherland the involvement of a second messenger in epinephrine's effect on liver cells?
A) Enzymatic activity...
Apoptosis involves all but which of the following?
Apoptosis involves all but which of the following?
A) fragmentation of the DNA
B) cell-signaling pathways
C) activation of cellular enzymes
D)...
Consider this pathway: epinephrine ? G protein-coupled receptor ? G protein ? adenylyl cyclase ? cAMP. Identify the second messenger.
Consider this pathway: epinephrine ? G protein-coupled receptor ? G protein ? adenylyl cyclase ? cAMP. Identify the second messenger.
A) cAMP
B)...
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because
A) only target...
The activation of receptor tyrosine kinases is characterized by
The activation of receptor tyrosine kinases is characterized by
A) dimerization and phosphorylation.
B) dimerization and IP3 binding.
C) a...
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?
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)...
Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because
Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because
A) they are species specific.
B)...
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.
Humans have receptors for two kinds of beta adrenergic compounds such as catecholamines to control cardiac muscle contractions. Some are beta 1 receptors...
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.
Affinity chromatography is a method that can be used to purify cell-surface receptors, while they retain their hormone-binding ability. A ligand (hormone)...
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.
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...
In the figure, the dots in the space between the two structures represent which of the following?
In the figure, the dots in the space between the two structures represent which of the following?
A) receptor molecules
B) signal transducers
C)...
Which of the following types of signaling is represented in the figure?
Which of the following types of signaling is represented in the figure?
A) autocrine
B) paracrine
C) hormonal
D) synaptic
E) long distance
Answer:...
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?
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...
Where do apoptotic signals come from?
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...
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?
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...
In C. elegans, ced-9 prevents apoptosis in a normal cell in which of the following ways?
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)...
Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell?
Why is apoptosis potentially threatening to the healthy "neighbors" of a dying cell?
A) Cell death would usually spread from one cell to the...
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?
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)...
Which of the following describes the events of apoptosis?
Which of the following describes the events of apoptosis?
A) The cell dies, it is lysed, its organelles are phagocytized, and its contents are...
Why has C. elegans proven to be a useful model for understanding apoptosis?
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...
GTPase activity is involved in the regulation of signal transduction because it
GTPase activity is involved in the regulation of signal transduction because it
A) increases the available concentration of phosphate.
B) decreases...
The termination phase of cell signaling requires which of the following?
The termination phase of cell signaling requires which of the following?
A) removal of the receptor
B) activation of a different set of relay...
What are scaffolding proteins?
What are scaffolding proteins?
A) ladderlike proteins that allow receptor-ligand complexes to climb through cells from one position to another
B)...
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?
At puberty, an adolescent female body changes in both structure and function of several organ systems, primarily under the influence of changing concentrations...
A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?
A drug designed to inhibit the response of cells to testosterone would almost certainly result in which of the following?
A) lower cytoplasmic...
In which of the following ways could signal transduction most probably be explored in research to treat cancer?
In which of the following ways could signal transduction most probably be explored in research to treat cancer?
A) removal of serine/threonine...
What explains the increased concentration of Ca?? in the ER?
What explains the increased concentration of Ca?? in the ER?
A) Calcium ions are actively imported from the cytoplasm into the ER.
B) Calcium...
The function of phosphatases in signal transduction is best described as to
The function of phosphatases in signal transduction is best described as to
A) move the phosphate group of the transduction pathway to the next...
Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction?
Which of the following amino acids are most frequently phosphorylated by protein kinases in the cytoplasm during signal transduction?
A) tyrosines
B)...
Which of the following is the best explanation for the fact that most transduction pathways have multiple steps?
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...
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
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....
Which of the following is a correct association?
Which of the following is a correct association?
A) kinase activity and the addition of a tyrosine
B) phosphodiesterase activity and the removal...
Which of the following statements is true of signal molecules?
Which of the following statements is true of signal molecules?
A) When signal molecules first bind to receptor tyrosine kinases, the receptors...
An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum?
An inhibitor of which of the following could be used to block the release of calcium from the endoplasmic reticulum?
A) tyrosine kinases
B)...
If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound
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...
If a pharmaceutical company wished to design a drug to maintain low blood sugar levels, one approach might be to design a compound
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...
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of
Caffeine is an inhibitor of phosphodiesterase. Therefore, the cells of a person who has recently consumed coffee would have increased levels of
A)...
Adenylyl cyclase has the opposite effect of which of the following?
Adenylyl cyclase has the opposite effect of which of the following?
A) protein kinase
B) protein phosphatase
C) phosphodiesterase
D) phosphorylase
E)...
An inhibitor of phosphodiesterase activity would have which of the following effects?
An inhibitor of phosphodiesterase activity would have which of the following effects?
A) block the response of epinephrine
B) decrease the amount...
Which of the following most likely would be an immediate result of growth factor binding to its receptor?
Which of the following most likely would be an immediate result of growth factor binding to its receptor?
A) protein kinase activity
B) adenylyl...
Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins?
Which of the following would be inhibited by a drug that specifically blocks the addition of phosphate groups to proteins?
A) G protein-coupled...
The toxin of Vibrio cholerae causes profuse diarrhea because it
The toxin of Vibrio cholerae causes profuse diarrhea because it
A) modifies a G protein involved in regulating salt and water secretion.
B)...
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?
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...
Sutherland discovered that epinephrine signals
Sutherland discovered that epinephrine signals
A) a decrease in levels of cAMP as a result of bypassing the plasma membrane.
B) lower blood...
In general, a signal transmitted via phosphorylation of a series of proteins
In general, a signal transmitted via phosphorylation of a series of proteins
A) brings a conformational change to each protein.
B) requires...
The receptors for a group of signaling molecules known as growth factors are often
The receptors for a group of signaling molecules known as growth factors are often
A) ligand-gated ion channels.
B) G protein-coupled receptors.
C)...
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?
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....
Since steroid receptors are located intracellularly, which of the following is true?
Since steroid receptors are located intracellularly, which of the following is true?
A) The receptor molecules are themselves lipids or glycolipids.
B)...
Because most receptors are membrane proteins, which of the following is usually true?
Because most receptors are membrane proteins, which of the following is usually true?
A) They lead to changes in intracellular ion concentration.
B)...
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?
One of the major categories of receptors in the plasma membrane reacts by forming dimers, adding phosphate groups, and then activating relay proteins....
Which of the following is true of transcription factors?
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...
Testosterone functions inside a cell by
Testosterone functions inside a cell by
A) acting as a signal receptor that activates tyrosine kinases.
B) binding with a receptor protein that...
Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP?
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...
Of the following, a receptor protein in a membrane that recognizes a chemical signal is most similar to
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...
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
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?
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,...
In which of the following ways do plant hormones differ from hormones in animals?
In which of the following ways do plant hormones differ from hormones in animals?
A) Plant hormones interact primarily with intracellular receptors.
B)...
In yeast signal transduction, the yeast cells
In yeast signal transduction, the yeast cells
A) must physically and directly interact.
B) produce signal molecules that change themselves so...
In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?
In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?
A) formation of mating complexes
B)...
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?
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...
Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction?
Which of the following is a likely explanation of why natural selection favored the evolution of signals for sexual reproduction?
A) Even in...
What is most likely to happen to an animal's target cells that lack receptors for local regulators?
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...
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,
Using the yeast signal transduction pathways, both types of mating cells release the mating factors. These factors bind to specific receptors on the...
Eyebrow hairs are always shorter than hairs on your head because ________.
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...
Male pattern baldness has a genetic switch that turns on in response to ________.
Male pattern baldness has a genetic switch that turns on in response to ________.
A) age
B) size
C) weight
D) male hormones
Answer:...
What is the first threat to life from a massive third-degree burn?
What is the first threat to life from a massive third-degree burn?
A) infection
B) catastrophic fluid loss
C) unbearable pain
D) loss of immune...
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?
Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage...
In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin?
In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the...
The sebaceous glands are simple alveolar glands that secrete a substance known as sebum. The secretion of sebum is stimulated ________.
The sebaceous glands are simple alveolar glands that secrete a substance known as sebum. The secretion of sebum is stimulated ________.
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?
Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these...
The composition of the secretions of the eccrine glands is ________.
The composition of the secretions of the eccrine glands is ________.
A) primarily uric acid
B) 99% water, sodium chloride, trace amounts of...
Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands?
Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands?
A) sebaceous and...
Which of the following statements best describes what fingernails actually are?
Which of the following statements best describes what fingernails actually are?
A) Fingernails are a modification of the epidermis.
B) Fingernails...
The most important factors influencing hair growth are ________.
The most important factors influencing hair growth are ________.
A) sex and hormones
B) age and glandular products
C) the size and number of...
A Langerhans' cell is a ________.
A Langerhans' cell is a ________.
A) specialized squamous epithelial cell
B) specialized phagocytic cell
C) specialized nerve cell
D) specialized...
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?
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...
Which of the following statements indicates the way in which the body's natural defenses protect the skin from the effects of UV damage?
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 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?
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...
The papillary layer of the dermis is connective tissue heavily invested with blood vessels. The superficial surface has structures called:
The papillary layer of the dermis is connective tissue heavily invested with blood vessels. The superficial surface has structures called:
A)...
Despite its apparent durability, the dermis is subject to tearing. How might a person know that the dermis has been stretched and/or torn?
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)...
The dermis has two major layers; which of the following constitutes 80% of the dermis and is responsible for the tension lines in the skin?
The dermis has two major layers; which of the following constitutes 80% of the dermis and is responsible for the tension lines in the skin?
A)...
The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis?
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...
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?
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...
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?
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...
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?
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...
Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________.
Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________.
A) provide the melanocyte with...
Keratinocytes are an important epidermal cell because ________.
Keratinocytes are an important epidermal cell because ________.
A) they produce a fibrous protein that gives the skin much of its protective...
The epidermis is responsible for protecting the body against invasion of bacteria and other foreign agents primarily because it is composed of ________.
The epidermis is responsible for protecting the body against invasion of bacteria and other foreign agents primarily because it is composed of ________.
A)...
The reason the hypodermis acts as a shock absorber is that ________.
The reason the hypodermis acts as a shock absorber is that ________.
A) it is located just below the epidermis and protects the dermis from...
Nutrients reach the surface of the skin (epidermis) through the process of ________.
Nutrients reach the surface of the skin (epidermis) through the process of ________.
A) absorbing materials applied to the surface layer of...
The ________ gland is a modified sudoriferous gland that secretes wax.
The ________ gland is a modified sudoriferous gland that secretes wax.
A) eccrine
B) apocrine
C) ceruminous
D) mammary
Answer: ...
Vernix caseosa is a ________.
Vernix caseosa is a ________.
A) substance contributing to acne during adolescence
B) whitish material produced by fetal sebaceous glands
C)...
The function of the root hair plexus is to ________.
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...
Although the integument is a covering, it is by no means simple, and some of its functions include ________.
Although the integument is a covering, it is by no means simple, and some of its functions include ________.
A) the dermis providing the major...
Sudoriferous glands vary in distribution over the surface of the body. Which of the following is correct?
Sudoriferous glands vary in distribution over the surface of the body. Which of the following is correct?
A) Eccrine are the most numerous,...
Which statement correctly explains why hair appears the way it does?
Which statement correctly explains why hair appears the way it does?
A) Kinky hair has flat, ribbonlike hair shafts.
B) Perfectly round hair...
Melanocytes ________.
Melanocytes ________.
A) are spidery-shaped cells in contact with cells in the stratum basale
B) are involved in the immune system
C) are involved...
Which of the following cutaneous receptors is specialized for the reception of touch or light pressure?
Which of the following cutaneous receptors is specialized for the reception of touch or light pressure?
A) Meissner's corpuscles
B) Pacinian...
If a splinter penetrated the skin into the second epidermal layer of the sole of the foot, which cells would be damaged?
If a splinter penetrated the skin into the second epidermal layer of the sole of the foot, which cells would be damaged?
A) granulosum
B) basale
C)...
Which muscles attached to the hair follicles cause goose bumps?
Which muscles attached to the hair follicles cause goose bumps?
A) arrector integument
B) arrector pili
C) levator folliculi
D) arrector folliculi
Answer:...
The dermis ________.
The dermis ________.
A) is an avascular connective tissue layer
B) has two layers
C) lacks sensory corpuscles and glands
D) is where melanocytes...
Acne is a disorder associated with ________.
Acne is a disorder associated with ________.
A) sweat glands
B) sebaceous glands
C) Meibomian glands
D) ceruminous glands
Answer:...
The major regions of a hair shaft include all of the following except ________.
The major regions of a hair shaft include all of the following except ________.
A) medulla
B) cortex
C) external root sheath
D) cuticle
Answer:...
A needle would pierce the epidermal layers of the forearm in which order?
A needle would pierce the epidermal layers of the forearm in which order?
A) basale, spinosum, granulosum, corneum
B) basale, spinosum, granulosum,...
_______ is an inherited condition that affects the heme pathway; it leaves the skin scarred and gums degenerated, and may have led to the folklore about vampires.
_______ is an inherited condition that affects the heme pathway; it leaves the skin scarred and gums degenerated, and may have led to the folklore about...
Select the most correct statement concerning skin cancer.
Select the most correct statement concerning skin cancer.
A) Most tumors that arise on the skin are malignant.
B) Squamous cell carcinomas arise...
What ion is sometimes used as a second messenger of amino acid based hormones?
What ion is sometimes used as a second messenger of amino acid based hormones?
A) iron
B) calcium
C) sodium
D) chlorine
Answer: ...
How do glucocorticoids enable the body to deal appropriately with stress?
How do glucocorticoids enable the body to deal appropriately with stress?
A) by increasing blood glucose, fatty acid, and amino acid levels and enhancing...
Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference?
Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this...
Which of the following organs is affected by thyroid hormone in adults?
Which of the following organs is affected by thyroid hormone in adults?
A) liver
B) spleen
C) thyroid gland
D) brain
Answer: ...
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 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...
Eicosanoids do not include ________.
Eicosanoids do not include ________.
A) paracrines
B) leukotrienes
C) hydrocortisones
D) prostaglandins
Answer: ...
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 ________.
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...
Which organ does not have hormone production?
Which organ does not have hormone production?
A) heart
B) kidney
C) liver
D) skin
Answer: ...
The only amine hormone to act like a steroid is ________.
The only amine hormone to act like a steroid is ________.
A) TH
B) ACTH
C) GH
D) ADH
Answer: ...
Aldosterone ________.
Aldosterone ________.
A) is secreted by the neurohypophysis
B) functions to increase sodium reabsorption
C) presence increases potassium concentration...
Which of the following is true about calcium homeostasis?
Which of the following is true about calcium homeostasis?
A) Increased calcitonin levels will cause increased blood calcium levels.
B) High calcium...
ACTH ________.
ACTH ________.
A) is secreted by the posterior pituitary
B) secretion is regulated by a hypothalamic secretion
C) causes the release of hormones from...
Regulating hormones from the hypothalamus ________.
Regulating hormones from the hypothalamus ________.
A) enter venous circulation and travel to the heart, which pumps the hormone-containing blood...
Cellular responses to hormones that initiate second-messenger systems include ________.
Cellular responses to hormones that initiate second-messenger systems include ________.
A) possible activation of several different second-messenger...
Which of the following would be associated with the action of steroids on cells?
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...
Which of the following is not a steroid-based hormone?
Which of the following is not a steroid-based hormone?
A) estrogen
B) aldosterone
C) epinephrine
D) cortisone
Answer: ...
The most important regulator of electrolyte concentrations in extracellular fluids is ________.
The most important regulator of electrolyte concentrations in extracellular fluids is ________.
A) insulin
B) aldosterone
C) glucagon
D) cortisol
Answer:...
Leptin is secreted by ________.
Leptin is secreted by ________.
A) lymphocytes
B) adipocytes
C) goblet cells
D) fibroblasts
Answer: ...
Mineralocorticoid is to aldosterone as glucocorticoid is to ________.
Mineralocorticoid is to aldosterone as glucocorticoid is to ________.
A) testosterone
B) estrogen
C) cortisol
D) epinephrine
Answer: ...
Which organ is responsible for synthesizing ANP?
Which organ is responsible for synthesizing ANP?
A) the heart
B) the kidney
C) the skin
D) the spleen
Answer: ...
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