EXAM 2

Question 1

Which of the following statements best describes the relationship between photosynthesis and cellular respiration?
A) Respiration runs the biochemical pathways of photosynthesis in reverse.
B) Photosynthesis occurs only in plants and respiration occurs only in animals.
C) Respiration is anabolic and photosynthesis is catabolic.
D) Photosynthesis stores energy in organic molecules, whereas respiration releases it.

Answer 1

D) Photosynthesis stores energy in organic molecules, whereas respiration releases it.

Question 2

Generation of proton gradients across membranes occurs during
A) photosynthesis.
B) respiration.
C) both photosynthesis and respiration.
D) neither photosynthesis nor respiration.
E) photorespiration.

Answer 2

C) both photosynthesis and respiration.

Question 3

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? 
A) CO₂ and glucose 
B) H₂O and O₂ 
C) ADP, Pi, and NADP⁺ 
D) electrons and H⁺ 
E) ATP and NADPH

Answer 3

E) ATP and NADPH

Question 4

Photosynthesis is not responsible for 
A) oxygen in the atmosphere. 
B) the ozone layer. 
C) most of the organic carbon on Earth's surface. 
D) atmospheric CO₂. 
E) fossil fuels.

Answer 4

E) fossil fuels

Question 5

Which of the following sequences correctly represents the flow of electrons during photosynthesis? 
A) NADPH → O₂ → CO₂ 
B) H₂O → NADPH → Calvin cycle 
C) NADPH → chlorophyll → Calvin cycle 
D) H₂O → photosystem I → photosystem II 
E) NADPH → electron transport chain → O₂

Answer 5

B) H₂O → NADPH → Calvin cycle

Question 6

How is photosynthesis similar in C₄ plants and CAM plants?
A) In both cases, only photosystem I is used.
B) Both types of plants make sugar without the Calvin cycle.
C) In both cases, rubisco is not used to fix carbon initially.
D) Both types of plants make most of their sugar in the dark.
E) In both cases, thylakoids are not involved in photosynthesis.

Answer 6

C) In both cases, rubisco is not used to fix carbon initially.

Question 7

Which of the following statements is a correct distinction between autotrophs and heterotrophs?
A) Only heterotrophs require chemical compounds from the environment.
B) Cellular respiration is unique to heterotrophs.
C) Only heterotrophs have mitochondria.
D) Autotrophs, but not heterotrophs, can nourish themselves beginning with CO₂ and other nutrients that are inorganic.
E) Only heterotrophs require oxygen.

Answer 7

D

Question 8

Which of the following does not occur during the Calvin cycle? 
A) carbon fixation 
B) oxidation of NADPH 
C) release of oxygen 
D) regeneration of the CO₂ acceptor 
E) consumption of ATP
Answer: C

Answer 8

C) release of oxygen

Question 9

In mechanism, photophosphorylation is most similar to
A) substrate-level phosphorylation in glycolysis.
B) oxidative phosphorylation in cellular respiration.
C) the Calvin cycle.
D) carbon fixation.
E) reduction of NADP⁺.
Answer: B

Answer 9

B) oxidative phosphorylation

Question 10

Which process is most directly driven by light energy?
A) creation of a pH gradient by pumping protons across the thylakoid membrane
B) carbon fixation in the stroma
C) reduction of NADP⁺ molecules
D) removal of electrons from chlorophyll molecules
E) ATP synthesis

Answer 10

D) removal of electrons from chlorophyll molecules

Question 11

Photosynthesis is not responsible for 
A) oxygen in the atmosphere. 
B) the ozone layer. 
C) most of the organic carbon on Earth's surface. 
D) atmospheric CO₂. 
E) fossil fuels.

Answer 11

E) fossil fuels.

Question 12

Where does the Calvin cycle take place?
A) stroma of the chloroplast
B) thylakoid membrane
C) cytoplasm surrounding the chloroplast
D) interior of the thylakoid (thylakoid space

Answer 12

A) stroma of the chloroplast

Question 13

In a plant cell, where are the ATP synthase complexes located?
A) thylakoid membrane only
B) plasma membrane only
C) inner mitochondrial membrane only
D) thylakoid membrane and inner mitochondrial membrane
E) thylakoid membrane and plasma membrane

Answer 13

D) thylakoid membrane and inner mitochondrial membrane

Question 14

The reactions that produce molecular oxygen (O₂) take place in

Answer 14

A) the light reactions alone.

Question 15

What color light is least effective in powering photosynthesis?
A) red
B) green
C) yellow
D) blue

Answer 15

B) green

Question 16

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they
A) fix CO₂ into organic acids during the night.
B) fix CO₂ into sugars in the bundle-sheath cells.
C) fix CO₂ into pyruvate in the mesophyll cells.
D) use the enzyme phosphofructokinase, which outcompetes rubisco for CO₂.
E) use photosystem I and photosystem II at night.

Answer 16

A) fix CO₂ into organic acids during the night.

Question 17

Which of the following is true of a species with a chromosome number of 2n = 16?

A) The species is diploid with 32 chromosomes per cell.

B) The species has 16 sets of chromosomes per cell.

C) Each cell has eight homologous pairs.

D) During the S phase of the cell cycle there will be 32 separate chromosomes.

Answer 17

C) Each cell has eight homologous pairs.

Question 18

When crossing an organism that is homozygous recessive for a single trait with a heterozygote, what is the chance of producing an offspring with the homozygous recessive phenotype?
A) 0%
B) 25%
C) 50%
D) 75%

Answer 18

C) 50%

Question 19

The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?
A) None of the traits obeyed the law of segregation.
B) The diploid number of chromosomes in the pea plants was 7.
C) All of the genes controlling the traits were located on the same chromosome.
D) All of the genes controlling the traits were on different chromosomes or far apart if on the same chromosome.

Answer 19

D) All of the genes controlling the traits were on different chromosomes or far apart if on the same chromosome.

Question 20

Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of the cross bbTT × BBtt will be expected to have black fur and long tails?
A) 1/16
B) 3/16
C) 1/2
D) 0

Answer 20

D) 0

Question 21

DNA molecules carry hereditary information in which of the following?
A) sequence of bases
B) phosphate-sugar backbones
C) side groups of nitrogenous bases
D) different five-carbon sugars

Answer 21

A) sequence of bases

Question 22

When Thomas Hunt Morgan crossed his red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies. Remarkably, all the white-eyed flies were male. What was the explanation for this result?
A) The gene involved is on the Y chromosome.
B) The gene involved is on the X chromosome.
C) The gene involved is on an autosome, but only in males.
D) Other male-specific factors influence eye color in flies.

Answer 22

B) The gene involved is on the X chromosome.

Question 23

What does “antiparallel” mean regarding the strands that make up DNA?
A) The twisting nature of DNA creates nonparallel strands.
B) The 5’ to 3’ direction of one strand runs counter to the 5’ to 3’ direction of the other strand.
C) Base pairings create unequal spacing between the two DNA strands.
D) One strand is positively charged and the other is negatively charged.

Answer 23

B) The 5’ to 3’ direction of one strand runs counter to the 5’ to 3’ direction of the other strand.

Question 24

Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?
A) primase
B) DNA ligase
C) DNA polymerase 
D) topoisomerase

Answer 24

C) DNA polymerase