Bio Lec Exam 2

Question 1

1

Answer 1

FALSE

The inner membrane of mitochondria is folded into cristae. Chloroplasts have thylakoid membranes.

Question 2

2

Answer 2

2) FALSE

All cells have a plasma membrane that
regulates the passage of molecules into and
out of the cell. Animal cells do not have a
cell wall.

Question 3

3

Answer 3

3) TRUE

It is true that mitochondria are thought to be
derived from aerobic bacteria that became
part of the eukaryotic cell through
endosymbiosis.

Question 4

4

Answer 4

4) TRUE

It is true that mitochondria and chloroplasts
are able to reproduce independently from the
division of the cell.

Question 5

5

Answer 5

5) TRUE

It is true that receptor-mediated endocytosis
involves the use of specific proteins in the
cell membrane.

Question 6

6

Answer 6

6) FALSE

It is true that the fluidity of a membrane
increases as the percentage of unsaturated
fatty acids in the phospholipids goes up. As
the percentage of unsaturated fatty acids
goes down, the membrane become less fluid

Question 7

7

Answer 7

False

In the cells that line the lumen of the small
intestine, it is tight junctions, not gap
junctions that keep materials in the digestive
tract from slipping between the cells and
entering the tissues.

Question 8

8

Answer 8

8) FALSE

In the sodium-potassium pump, sodium is
transported out of the cell and potassium is
transported into the cell using ATP energy.

Question 9

9

Answer 9

9) FALSE

The process by which a white blood cell or
an amoeba engulfs bacteria is called
phagocytosis. Pinocytosis is “cell drinking”
and instead of solid particles, the cell
engulfs small droplets of liquid or very tiny
particles.

Question 10

10

Answer 10

10) TRUE

It is true that an extracellular matrix helps
some cells to adhere to neighboring cells.

Question 11

11

Answer 11

11) TRUE

If a change in pH alters an allosteric site
where an inhibitor binds, but doesn’t change
the active site for the intended substrate, it
would be possible for an enzymatically
controlled reaction to occur as normal. This
is a true statement.

Question 12

12

Answer 12

12) TRUE

In order to roll a rock down a hillside, you
must first push it up the hill. It is true that
pushing the rock is analogous to the energy
of activation of a chemical reaction

Question 13

13

Answer 13

True

Enzyme inhibition is the process that turns
off an early enzyme in a metabolic pathway.
This can occur when the product of the
pathway acts as an inhibitor. This is a true
statement.

Question 14

14

Answer 14

14) FALSE

This is a false statement. Enzymes are
proteins that speed up chemical reactions.

Question 15

15

Answer 15

15) [A, C, D]

Bacterial cells have a cell wall, a cell
membrane, and ribosomes (along with
cytosol) but do not have any membrane-
bound organelles such as a nucleus or a
Golgi apparatus.

Question 16

16

Answer 16

16) [A, B, C]

Eukaryotic cells in general will not be
affected by penicillin. Animal cells do not
have a cell wall and plant cell walls are
constructed differently from bacterial cell
walls. It is also true that bacteria that have
already formed their cell walls would be
unaffected and that penicillin would stop the
growth of active colonies of susceptible
bacteria.

Question 17

17

Answer 17

17) [A, B, C]

The bacteria cell wall is located outside the
cell membrane. There may or may not be
fimbriae present on the outside of the cell.
Inside the cell there may be plasmids and
DNA, but the DNA is not separated from the
rest of the cell by a membrane. The
glycocalyx, which has a protective function,
lies outside of the cell membrane

Question 18

18

Answer 18

A, B, D

Microtubules are important for maintaining
cell shape, for moving chromosomes during
cell division and for moving materials across
the surface of respiratory cells. Microtubules
do not play a role in the breakdown of fatty
acids and lipids. That is accomplished by the
peroxisome.

Question 19

19

Answer 19

19) [C, D, E]

Plant cells and prokaryotic cells have a cell
wall. Animal cells do not. The functions of
the cell wall are to shape, support, and
protect the cell.

Question 20

20

Answer 20

20) [A, C]

Question 21

21

Answer 21

21) [A, B, C, D]

The major functions of the plasma
membrane include everything but the
production of proteins used in construction
of the cell wall.

Question 22

22

Answer 22

22) [A, D, E]

The extracellular matrix can help cells
adhere to neighboring cells, and can be
made of collagen and elastin. It influences
the activities of the cytoskeleton and,
therefore, the shape and activities of a cell.

Question 23

23

Answer 23

23) [C, D, E]

The binding of a chemical messenger to a
membrane receptor usually initiates a
cascade of reactions called the signal
transduction pathway which can cause
changes in the shape or movement of a cell
or the activation of an enzyme. The
chemical messenger may also affect
activities in the nucleus. For example, it can
cause a gene to be activated.

Question 24

24

Answer 24

24) [B, D, E]

Cyclic AMP and calcium ions are common
second messengers. Cyclic AMP usually
activates an enzyme in a second messenger
system. Second messenger systems usually
amplify the cellular response to a chemical
messenger.

Question 25

25

Answer 25

25) [A, D]

If a change in pH alters the allosteric site
where an inhibitor binds, the enzyme’s
activity would not be affected but the
inhibitor would no longer decrease the
activity of the enzyme.

Question 26

26

Answer 26

26) D

Only autotrophic eukaryotic cells contain
chloroplasts. Heterotrophic and autotrophic
cells have mitochondria.

Question 27

27

Answer 27

27) D

The rough ER and the smooth ER both
transport molecules to other parts of the cell
via vesicles. One of the many functions of
the cytoskeleton is to move organelles
around the cell. Ribosomes do not assist in
the movement of materials throughout the
cell.

Question 28

28

Answer 28

28) E

After being formed by the ribosomes located
on the endoplasmic reticulum, proteins are
transported to the Golgi in vesicles. Vesicles
are also used to ship proteins out of the
Golgi

Question 29

29

Answer 29

D

The cell theory states that all cells come
from preexisting cells and therefore it does
not state that bacteria and other small
organisms can arise spontaneously. All other
choices are correct.

Question 30

30

Answer 30

30) C

In light of the cell theory that “all living
things are composed of cells,” the general
concept still holds because these organisms
are cellular at specific stages in their life
cycle.

Question 31

31

Answer 31

31) C

Golgi apparatus give rise to both lysosomes
and vesicles.

Question 32

32

Answer 32

32) D

Cells are the smallest unit of life.

Question 33

33

Answer 33

33) A

The nucleoid region is unique to bacterial cells.

Question 34

34

Answer 34

34) A

Question 35

35

Answer 35

35) B

The cell wall would function to provide a
rigid wall that prevents the cell from
swelling.

Question 36

36

Answer 36

36) C

Question 37

37

Answer 37

37) A

It is believed that both mitochondria and
chloroplasts were engulfed by larger
eukaryotic cells.

Question 38

38

Answer 38

38) C

Question 39

39

Answer 39

39) C

Question 40

40

Answer 40

40) B

Chloroplasts are to photosynthesis as
mitochondria are to aerobic respiration

Question 41

41

Answer 41

D

Proteins are synthesized by ribosomes and
lipids are made in the smooth endoplasmic
reticulum.

Question 42

42

Answer 42

42) B

Without a cytoskeleton, eukaryotic cells
would not have an efficient way to transport
materials from one organelle to another.

Question 43

43

Answer 43

43) A

Question 44

44

Answer 44

44) E

Membrane-bounded vesicles that break
down fatty acids while producing hydrogen
peroxide as a waste product are
peroxisomes.

Question 45

45

Answer 45

45) C

Mitochondria have a double membrane.

Question 46

46

Answer 46

46) C

Question 47

47

Answer 47

47) D

The cells that line our respiratory tract, and
one-celled paramecia both have short hair
like projections called cilia.

Question 48

48

Answer 48

48) C

The Golgi is responsible for packaging up
materials received from the ER and assisting
in their secretion from the cell.

Question 49

49

Answer 49

49) B

The most likely explanation for the bad taste
of meat that has “freezer burn” from
repeated freezing is the destruction of
lysosomes and resultant autodigestion

Question 50

50

Answer 50

C

Golgi apparatus give rise to both lysosomes
and vesicles.

Question 51

51

Answer 51

51) D

All cells have these two characteristics: a
plasma membrane and ribosomes in the
cytoplasm.

Question 52

52

Answer 52

52) B

This leads us to conclude that most cell
components are constantly broken down and
rebuilt.

Question 53

53

Answer 53

53) A

Adequate surface area (plasma membrane)
is needed to furnish nutrients to and expel
wastes from the volume (cytoplasm).

Question 54

54

Answer 54

54) D

The plant cell’s central vacuole provides the
plant cell with support, stores nutrients and
cellular waste products, and is a reservoir for
water. All of the choices are correct.

Question 55

55

Answer 55

55) C

The only structure NOT associated with
mitochondria is stroma. Stroma is found in
chloroplasts.

Question 56

56

Answer 56

56) C

Multicellular organisms are composed of a
variety of different cell types.

Question 57

57

Answer 57

57) B

The ribosome synthesizes proteins based on
the information it receives in an mRNA
molecule.

Question 58

58

Answer 58

58) D

All are correct except that the ribosomes do
not carry out cellular respiration.

Question 59

59

Answer 59

59) A

The nucleus is the most prominent cellular
structure.

Question 60

60

Answer 60

60) A

Protein synthesis begins when mRNA
makes a copy of a gene and carries that copy
out of the nucleus to a ribosome located in
the cytoplasm.

Question 61

61

Answer 61

61) B

The nuclear envelope contains pores which
allow the mRNA to exit the nucleus.

Question 62

62

Answer 62

62) B

Vesicles from the Golgi apparatus are made
of the same phospholipid structure as the
cell membrane, therefore the vesicles are
able to easily fuse with the cell membrane.

Question 63

63

Answer 63

63) D

The peroxisomes are responsible for
breaking down lipids within the cell.

Question 64

64

Answer 64

64) D

ATP is generally not stored in vacuoles.

Question 65

65

Answer 65

65) A

Actin filaments are found in the cell
membrane of amoebas that help facilitate
movement.

Question 66

66

Answer 66

66) B

The motor molecule myosin is responsible
for pulling the actin filament along

Question 67

67

Answer 67

C

The inner membrane system of the
mitochondria is called the cristae.

Question 68

68

Answer 68

68) D

Cholesterol is lipid in nature and a steroid. It
regulates the fluidity of animal cell
membranes. Integral proteins do not serve
this function.

Question 69

69

Answer 69

69) C

Both of these answer choices are correct.
Proteins in a membrane are peripheral if
they are on the inside surface and held in
place by the cytoskeleton. Integral proteins
are embedded in the membrane and may
protrude through either surface of the
bilayer.

Question 70

70

Answer 70

70) C

Question 71

71

Answer 71

71) A

Question 72

72

Answer 72

72) B

The newly discovered membrane channel
protein that accounts for the quick
movement of water across a membrane is
called an aquaporin.

Question 73

73

Answer 73

73) C

Question 74

74

Answer 74

74) E

Question 75

75

Answer 75

75) D

Question 76

76

Answer 76

76) E

Question 77

77

Answer 77

77) B

Question 78

78

Answer 78

78) C

The blood type proteins are located on the
outer surface of the red blood cell
membrane.

Question 79

79

Answer 79

E

Whether a molecule can cross the plasma
membrane depends upon the size of the
molecule, the shape of the molecule, the
chemical properties of the molecule, and the
charge of the molecule. The number of
double bonds in the molecule does not affect
its ability to cross a membrane.

Question 80

80

Answer 80

80) B

A glass of water is hypotonic to the celery
cells because it has a lower concentration of
solute than the celery cells. In this solution,
water will move into the celery cells from
the surrounding solution.

Question 81

81

Answer 81

81) B

Osmosis is the movement of water across a
semipermeable membrane from an area of
higher water concentration to an area of
lower water concentration.

Question 82

82

Answer 82

82) D

The sequence of the mitochondrial DNA in
the cell to be transplanted would not affect
its ability to be transplanted. The cell
recognition proteins, major
histocompatibility complex proteins, and
carbohydrate chains in the membranes of the
cells in the tissues to be transplanted all
effect the ability of the tissues to be
transplanted.

Question 83

83

Answer 83

83) A

Since the interior of the cell is hydrophobic,
polar molecules and ions cannot readily pass
through the membrane. Many of these
molecules and ions will require both energy
and transport proteins to move in and out of
the cell

Question 84

84

Answer 84

84) E

Freshwater protozoans react to a hypotonic
environment by removing water through a
contractile vacuole.

Question 85

85

Answer 85

85) B

Question 86

86

Answer 86

86) E

Cells change their chemical identity on a
regular basis by producing different
glycolipids and glycoproteins internally and
moving them into the plasma membrane.

Question 87

87

Answer 87

87) B

Plants show turgor pressure when their cells
contain water vacuoles that are full of water.

Question 88

88

Answer 88

88) E

Active transport is the movement of a
substance against its concentration through
the release of energy from ATP.

Question 89

89

Answer 89

89) A

Sugars and amino acids are carried into the
cell by means of facilitated transport.

Question 90

90

Answer 90

90) D

The process by which cholesterol is
transported into the cell by binding of LDL
to its receptor and the internalization of the
receptor-LDL complex is by receptor-
mediated endocytosis.

Question 91

91

Answer 91

91) A

The solution in the tube has a higher
concentration of solute than the solution in
the beaker. It is, therefore, hypertonic.

Question 92

92

Answer 92

92) B

The highest concentration of water is in the
5% solution (95% water, 5% solute).

Question 93

93

Answer 93

93) C

As diffusion occurs, the 10% solution will
become less concentrated and the 5%
solution will become more concentrated.

Question 94

94

Answer 94

94) A

The process should be identified as
facilitated transport because of the
movement of solute from a higher to lower
concentration through a carrier protein.

Question 95

95

Answer 95

95) C

In an isotonic environment, there would be
no net movement of water.

Question 96

96

Answer 96

96) E

Plasma membranes of eukaryotic cells DO
NOT contain pores that allow materials to
pass freely through the membrane. Such
pores would prevent the cell from being able
to maintain homeostasis.

Question 97

97

Answer 97

97) D

Collagen provides the cell with the ability to
resist stretching.

Question 98

98

Answer 98

98) B

The cell membrane would have to include a
proton pump to rid the cytoplasm of
excess protons, thus increasing the pH.

Question 99

99

Answer 99

99) D

If a living plant were moved from a
freshwater aquarium to a saltwater
aquarium, the plant’s cells would lose water
and plasmolysis would occur

Question 100

100

Answer 100

D

The reason plants wilt if they are watered
with a salt solution is due to loss of water
and the resulting decrease in turgor pressure.

Question 101

101

Answer 101

101) A

Active transport is used to move ions against
a concentration gradient.

Question 102

102

Answer 102

102) C

Active transport requires large amounts of
energy. If the mitochondria cease to function
the active transport in the kidneys would
decrease.

Question 103

103

Answer 103

103) B

Preventing the mixing of cellular contents
during endocytosis is worth the energy
expended.

Question 104

104

Answer 104

104) B

Endocytosis, pinocytosis, and receptor-
mediated endocytosis are processes that
draw substances into the cell. Cellular
wastes would be removed from the cell
through the process of exocytosis.

Question 105

105

Answer 105

105) D

Question 106

106

Answer 106

106) C

Question 107

107

Answer 107

107) A

Question 108

108

Answer 108

108) D

Animal cells do not contain plasmodesmata.
Plasmodesmata are found between plant
cells.

Question 109

109

Answer 109

109) A

Question 110

110

Answer 110

110) A

Question 111

111

Answer 111

111) B

The process by which a white blood cell or
an amoeba engulfs bacteria is called
phagocytosis.

Question 112

112

Answer 112

112) C

Each cell has a number of different plasma
membrane receptors, each of which can bind
a specific chemical messenger. Different cell
types have different plasma membrane
receptors and therefore are only affected by
certain chemical messengers.

Question 113

113

Answer 113

113) B

Endocrine cell signals are hormones
produced by one organ or tissue of the body
to influence the function of another organ or
tissue.

Question 114

114

Answer 114

114) E

All of the biochemical pathways in a cell
constitute metabolism.

Question 115

115

Answer 115

115) B

Mitochondria and chloroplasts are involved
in a redox cycle. Carbon dioxide is reduced
during photosynthesis and the resulting
carbohydrate is oxidized during cellular
respiration.

Question 116

116

Answer 116

116) D

All of these factors might increase the
activity of an enzyme except the presence of
other enzymes.

Question 117

117

Answer 117

117) A

Question 118

118

Answer 118

118) B

The first law of thermodynamics states that
energy is not created nor destroyed, but it
can change from one energy form to
another.

Question 119

119

Answer 119

119) D

The second law states that some useful
energy is lost as heat whenever an energy
transfer occurs.

Question 120

120

Answer 120

120) D

When an organism dies, the chemical
compounds in their cells lose their
organization over time because there is no
longer an input of energy to maintain the
organized state.

Question 121

121

Answer 121

121) C

Endergonic reactions can only occur if there
is an input of energy.

Question 122

122

Answer 122

122) B

The statement that is NOT a consequence of
the second law of thermodynamics is:
Reactions that occur spontaneously are those
that increase the amount of useful energy in
a system.

Question 123

123

Answer 123

123) B

Coupling occurs when the energy released
by an exergonic reaction is used to drive an
endergonic reaction.

Question 124

124

Answer 124

124) A

The subunits from which ATP is made are
ADP and phosphate.

Question 125

125

Answer 125

125) C

ATP is considered to be a molecule that
carries a great deal of chemical energy in a
chemical bond.

Question 126

126

Answer 126

126) D

ATP is considered a high-energy compound
because under cellular conditions, 7.3 kcal
per mole of energy is released when a bond
is broken between the adenosine
diphosphate and the third phosphate.

Question 127

127

Answer 127

127) D

The currently accepted theory of how an
enzyme and its substrate fit together is the
induced fit model: As the substrate binds to
the enzyme, the shape of the active site
changes to accommodate the reaction.

Question 128

128

Answer 128

128) D

It is not true that an enzyme’s activity is
generally reduced by an increase in substrate
concentration. Enzyme activity will increase
as substrate concentration increases, until
the maximum rate is reached.

Question 129

129

Answer 129

129) E

Competitive inhibitors act by binding to the
enzyme’s active site to that the substrate(s)
cannot. Competitive inhibitors do not
denature the enzyme.

Question 130

130

Answer 130

130) C

A coenzyme is a nonprotein organic cofactor
that interacts with an enzyme to allow it to
work.

Question 131

131

Answer 131

131) C

A muscle contracting is a form of kinetic
energy, not potential energy

Question 132

132

Answer 132

132) D

In coupled reactions an exergonic reaction
releases energy, often captured in the form
of ATP, that is then used to power an
endergonic reaction.

Question 133

133

Answer 133

133) D

Strong acids and bases, and temperatures
above 100o C will denature a protein. A
missing coenzyme would slow or stop an
enzyme but would not denature it.

Question 134

134

Answer 134

134) D

Question 135

135

Answer 135

135) B

This is illustrative of the second law of
thermodynamics.

Question 136

136

Answer 136

136) C

Eventually, sunlight that is absorbed on the
earth returns to space as dispersed heat.

Question 137

137

Answer 137

137) A

The cellular energy expended in “thinking”
must be less than the chemical bond energy
supplied in food to these brain cells, since
entropy increases with every energy
transformation.

Question 138

138

Answer 138

138) A

Compared with conditions today, the
entropy of the universe then will have
greatly increased.

Question 139

139

Answer 139

139) B

The reaction would continue since there is
plenty of substrate. The reaction would also
speed up since room temperature is warmer
than the refrigerator.

Question 140

140

Answer 140

140) E

If there are twelve different intermediate
products produced in the stages for
production of a molecule in a cell, we can
expect that there are about twelve enzymes,
at least one responsible for each step in the
metabolic pathway.

Question 141

141

Answer 141

141) E

Both taking lactase enzyme and avoiding all
dairy products would be correct.

Question 142

142

Answer 142

142) D

NAD is oxidized while NADH is reduced.

Question 143

143

Answer 143

143) C

The letter “A” depicts the energy of
activation.

Question 144

144

Answer 144

144) C

The letter “B” depicts the energy of the
reactants, while “C” depicts the energy of
the products.

Question 145

145

Answer 145

145) A

The reaction in the graph is exergonic
because the end product has less energy than
the reactant.

Question 146

146

Answer 146

146) D

The metabolic pathway involves four
possible chemical reactions.

Question 147

147

Answer 147

147) A

A is the first reactant (substrate) of this
metabolic pathway and E is the end product
of the pathway.

Question 148

148

Answer 148

148) B

ADP → ATP is endergonic and B → C is
exergonic.

Question 149

149

Answer 149

149) A

C → D on the pathway is an endergonic
reaction, which is coupled with the
exergonic reaction, ATP → ADP.

Question 150

150

Answer 150

150) A

Glucose and oxygen are required substrates
for cellular respiration.

Question 151

151

Answer 151

151) A

Glucose and oxygen are the end products of
photosynthesis.

Question 152

152

Answer 152

152) A

The missing substrate is 6H2O.

Question 153

153

Answer 153

153) D

All of these are examples of potential
energy.

Question 154

154

Answer 154

154) A

The rest of the energy is converted into heat.

Question 155

155

Answer 155

155) A

Question 156

156

Answer 156

156) A

Potential energy is stored energy, which is
then converted into kinetic energy.

Question 157

157

Answer 157

157) D

If somehow scientists and engineers created
an engine that converts 100% of the energy
present in diesel fuel into moving a truck
down the road that would NOT be consistent
with the 2nd Law of Thermodynamics.