bio exam pratice questions

8/2/2019 Bio Exam Pratice Questions

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1. A carbon atom bound to another carbon atom may transiently attract a hydrogen atom that

is bound to a carbon atom. The best explanation for this fact is:

a) Carbon to carbon bonds are, in actuality, slightly polar.

b) Electrons may accumulate by chance in one part of a molecule creating a region of

charge.

c) Carbon to hydrogen bonds are, in actuality, slightly polar.

d) Electrons usually spend significantly more time around one of the two atoms

participating in a covalent bond, even if this bond is nonpolar covalent.

e) Atoms participating in covalent bonds are not always stable.

2. Oxygen is a strongly electronegative element. This fact means all of the following except:

a) An oxygen atom tends to exert a stronger pull on the electrons it shares with a less

electronegative atom than the other atom does.

b) Oxygen atoms tend to form polar covalent bonds with less electronegative atoms.

c) An oxygen atom may carry a partial negative charge when bound to less

electronegative atoms.

d) In the periodic table, oxygen is found in the second to last column on the right side

(next to the column containing the noble gases).

e) There is no incorrect answer choice above.

3. Which of the following statements about ions is false?

a) Once an atom ionizes, the number of its protons no longer equals the number of its

electrons.

b) An anion has more electrons orbiting its nucleus than it has protons in its nucleus.

c) Regardless of its charge, an ion can easily interact with water molecules in an aqueous

solution.

d) Ions are less stable than neutral atoms with unfilled outermost energy levels.

e) A cation can attract an anion even if they did not exchange an electron with one

another in the process of becoming ions.


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4. The compound NaCl comes apart in water because:

a) Hydrogen bonds are stronger in water than ionic bonds.

b) Covalent bonds are stronger in water than ionic bonds.

c) Ionic bonds are stronger in water than hydrogen bonds.

d) The oxygen atoms of the water molecules surround the chloride ions.e) The hydrogen atoms of the water molecules surround the chloride ions.

5. A particular fat is solid at room temperature. Which of the following statements is most

likely true?

a) The hydrocarbon chains of the fatty acids of the triglyceride are polyunsaturated.b) The hydrocarbon chains of the fatty acids of the triglyceride contain many cis double

bonds.

c) The hydrocarbon chains of the fatty acids of the triglyceride are fully saturated withhydrogen atoms.

d) The hydrocarbon chains of the fatty acids of the triglyceride contain no trans doublebonds.

e) The hydrocarbon chairs of the fatty acid of the triglyceride are mostly polar and allowfor extensive van der Waals interactions.

6. Which of the following statements about water molecules is false?

a) The cohesion of water molecules to one another creates a surface tension at an airwater interface.

b) There are fewer hydrogen bonds between an individual water molecule and itsneighbors in ice than in the liquid phase.

c) The numerous hydrogen bonds between water molecules in the liquid phase accountfor the high heat of vaporization of water.

d) The numerous hydrogen bonds between water molecules in the liquid phase accountfor the high specific heat of water.

e) There are no false statements above


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7. A change in the quaternary structure of a protein would most likely:

a) Lead to a change in the primary structure of the protein.

b) Lead to a change in the function of this protein, but only if this protein was composed

of one polypeptide.c) Lead to a change in the van der Waals interactions of the secondary structure.

d) Not have an effect on the function of this protein.

e) None of the above

8. Two hydrophobic amino acids (such as isoleucine and valine) would be found on the ______

if that protein _______.

Fill in the blanks with answer choices that correctly complete the sentence.

a) Outside of a globular protein; was found in the cytoplasm.

b) Inside of a globular protein; was embedded in the fatty acid portion of the lipid bilayer.

c) Inside of a globular protein; was found in the cytoplasm.

d) Outside of a globular protein; was found in an aqueous solution.

e) Inside of a globular protein; was found in a nonpolar solution.

9. Which of the following statements about a strand of RNA is true?

a) The number of purines equals the number of pyrimidines in the strand.

b) Three of the RNA nucleotides contain doubleringed nitrogenous bases.

c) The sugar of an RNA nucleotide is less polar than the sugar of a DNA nucleotide.d) There is no 5 3 directionality in an RNA strand.

e) There are no true statements above.

10. A phospholipid in a lipid bilayer can differ from a second phospholipid in that same bilayer

in all of the following ways except:

a) The number of carbons in its fatty acid tails.

b) The number of carbontocarbon double bonds in its fatty acid tails.

c) The number of fatty acid tails it contains.d) The position of double bonds within its fatty acids tails.

e) The identity of the head group attached to the phosphate group.


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Answers:

1. b2. d3. d4. e5. c6. b7. e8. c9. e10.c

bio exam pratice questions

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