BIO101: Mastering Biology Sample Questions

Why does ice float in liquid water? a) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water. b) The crystalline lattice of ice causes it to be denser than liquid water. c) The liquid water molecules have more kinetic energy and thus support the ice. d) Ice always has air bubbles that keep it afloat. e) The ionic bonds between the molecules in ice prevent the ice from sinking.

a) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.

What determines the types of chemical reactions that an atom participates in? a) the number of electrons in the outermost electron shell b) the number of electrons in the innermost electron shell c) its atomic number d) the number of protons it contains e) its atomic mass

a) The number of electrons in the outermost electron shell

Which of the following is true of both starch and cellulose? a) They are both polymers of glucose. b) They are both structural components of the plant cell wall. c) They are both used for energy storage in plants. d) They can both be digested by humans. e) They are geometric isomers of each other.

a) They are both polymers of glucose

In salt, what is the nature of the bond between sodium and chlorine? a) ionic b) polar covalent c) hydrophobic d) hydrogen e) nonpolar covalent

a) ionic

Which of these is a source of lactose? a) milk b) starch c) potatoes d) sugar beets e) sugar cane

a) milk

Many mammals control their body temperature by sweating. Which property of water is most directly responsible for the ability of sweat to lower body temperature? a) the absorption of heat by the breaking of hydrogen bonds b) water's high surface tension c) the release of heat by the formation of hydrogen bonds d) water's change in density when it condenses e) water's ability to dissolve molecules in the air

a) the absorption of heat by the breaking of hydrogen bonds

Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have? a) 9 b) 10 c) 81 d) 19 e) 28

b) 10

The innermost electron shell of an atom can hold up to _____ electrons. a) 1 b) 2 c) 8 d) 18 e) 32

b) 2

Glycogen is _____. a) the form in which plants store sugars b) a polysaccharide found in animals c) a polysaccharide found in plant cell walls d) a source of saturated fat e) a transport protein that carries oxygen

b) a polysaccharide found in animals

Water's high specific heat is mainly a consequence of the a) small size of the water molecules. b) absorption and release of heat when hydrogen bonds break and form. c) high specific heat of oxygen and hydrogen atoms. d) fact that water is a poor heat conductor. e) inability of water to dissipate heat into dry air.

b) absorption and release of heat when hydrogen bonds break and form

Atoms with the same number of protons but with different electrical charges _____. a) have different numbers of neutrons b) are different ions c) have different atomic numbers d) are different isotopes e) have different atomic masses

b) are different ions

Which of the following is not a polymer? a) chitin b) glucose c) DNA d) starch e) cellulose

b) glucose

glucose + glucose —> _____ by _____. a) starch + water ... dehydration synthesis b) maltose + water ... dehydration synthesis c) sucrose + water ... dehydration synthesis d) cellulose + water ... hydrolysis e) lactose + water ... hydrolysis

b) maltose + water ... dehydration synthesis

What is the pH of a solution with a hydrogen ion [H+] concentration of 10-8 M? a) pH 4 b) pH 8 c) pH 6 d) pH 10 e) pH 2

b) pH 8

How many electron pairs does carbon share in order to complete its valence shell? a) 8 b) 2 c) 4 d) 3 e) 1

c) 4

Which of these relationships is true of an uncharged atom? a) The atomic mass is equal to the atomic number. b) The number of electrons is equal to the number of neutrons. c) The number of protons is equal to the number of electrons. d) The atomic mass is equal to the number of electrons. e) The number of neutrons is equal to the number of protons.

c) The number of protons is equal to the number of electrons.

Which of these refers to atoms with the same atomic number but different atomic masses? a) These atoms have different numbers of protons. b) These atoms have different numbers of electrons. c) These atoms are isotopes. d) These atoms are different elements. e) These atoms are isomers.

c) These atoms are isotopes.

Which of these is a polysaccharide? a) lactose b) glucose c) cellulose d) galactose e) sucrose

c) cellulose

Water is able to form hydrogen bonds because a) the water molecule is shaped like a tetrahedron. b) each of the hydrogen atoms in a water molecule is weakly negative in charge. c) the bonds that hold together the atoms in a water molecule are polar covalent bonds. d) the oxygen atom in a water molecule has a weak positive charge. e) oxygen has a valence of 2.

c) the bonds that hold together the atoms in a water molecule are polar covalent bonds

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have? a) 6 b) 11 c) 16 d) 5 e) 0

d) 5

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons? a) 12 b) -1 c) 0 d) 6 e) 18

d) 6

Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? a) mass number b) mass weight c) atomic mass d) atomic number e) atomic weight

d) atomic number

_____ is the most abundant organic compound on Earth. a) Starch b) Lactose c) Glucose d) Glycogen e) Cellulose

e) Cellulose

Which of the following is true of cellulose? a) It is a polymer composed of sucrose monomers. b) It is a storage polysaccharide for energy in plant cells. c) It is a storage polysaccharide for energy in animal cells. d) It is a major structural component of animal cell plasma membranes. e) It is a major structural component of plant cell walls.

e) It is a major structural component of plant cell walls.

An ionic bond involves _____. a) no atoms other than sodium and chlorine b) water avoidance c) the sharing of a single pair of electrons d) the unequal sharing of an electron pair e) an attraction between ions of opposite charge

e) an attraction between ions of opposite charge

If the pH of a solution is decreased from 9 to 8, it means that the a) concentration of OH- has increased 10-fold (10X) compared to what it was at pH 9; concentration of H+ remains unchanged. b) concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9; concentration of OH- remains unchanged. c) concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9; concentration of OH- remains unchanged. d) concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9; concentration of H+ remains unchanged. e) concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9 and concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9.

e) concentration of H+ has increased 10-fold (10X) compared to what it was at pH 9 and concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9.

What is the chemical mechanism by which cells make polymers from monomers? a) ionic bonding of monomers b) the formation of disulfide bridges between monomers c) phosphodiester linkages d) hydrolysis e) dehydration reactions

e) dehydration reactions

Which type of bond must be broken for water to vaporize? a) polar covalent bonds b) nonpolar covalent bonds c) covalent bonds d) ionic bonds e) hydrogen bonds

e) hydrogen bonds

The bonds that are broken when water vaporizes are a) covalent bonds between atoms within water molecules. b) nonpolar covalent bonds c) polar covalent bonds. d) ionic bonds. e) hydrogen bonds between water molecules.

e) hydrogen bonds between water molecules

A(n) _____ refers to two or more atoms held together by covalent bonds. a) isotope b) shell c) community d) ion e) molecule

e) molecule