Question 1

Which of the following best describes the main difference between autotrophs and heterotrophs in terms of energy acquisition?

Accepted Answer

Autotrophs produce their own organic molecules from inorganic materials, while heterotrophs must consume organic matter for energy.

Question 2

During cellular respiration, which molecule is oxidized and which is reduced? Select the correct pair.

Accepted Answer

$$\mathrm{O_2$} is $$reduced; $$\mathrm{C_6H_{12}O_6$} is $$oxidized.

Question 3

Which of the following statements about the mitochondrial inner membrane is correct?

Accepted Answer

It contains folds called cristae that increase surface area for the electron transport chain.

Question 4

A plant leaf appears green because:

Accepted Answer

Chlorophyll reflects and transmits green wavelengths while absorbing others.

Question 5

Which of the following best explains the role of carotenoids in photosynthesis?

Accepted Answer

They absorb blue-green light and provide photoprotection by dissipating excess energy.

Question 6

During glycolysis, what is the net production of ATP and NADH per molecule of glucose?

Accepted Answer

2 ATP and 2 NADH

Question 7

Which of the following correctly describes the fate of pyruvate during aerobic respiration?

Accepted Answer

It enters the mitochondrial matrix, loses a $$\mathrm{CO_2$}$$, is joined by CoA, and is converted into Acetyl CoA.

Question 8

In the citric acid (Krebs) cycle, which of the following events occurs?

Accepted Answer

Acetyl CoA combines with OAA to form citric acid, which is then oxidized, producing $$\mathrm{CO_2$}$$, NADH, FADH$$_2$$, and ATP.

Question 9

Which process in cellular respiration produces the majority of ATP per glucose molecule?

Accepted Answer

Oxidative phosphorylation (including chemiosmosis)

Question 10

A poison that blocks the passage of electrons along the electron transport chain would directly result in which of the following?

Accepted Answer

A buildup of NADH and FADH$$_2$$ and a halt in ATP production by oxidative phosphorylation

Question 11

During the light reactions of photosynthesis, what is the primary function of water splitting?

Accepted Answer

To provide electrons to Photosystem II and generate a proton gradient for ATP synthesis

Question 12

Which of the following best describes the flow of electrons during the light reactions of photosynthesis?

Accepted Answer

From water to Photosystem II to Photosystem I to NADP$$^+$$

Question 13

The enzyme rubisco is directly involved in which step of the Calvin cycle?

Accepted Answer

Carbon fixation, by attaching CO$$_2 to $$RuBP

Question 14

If a plant is exposed only to green light, what would most likely happen to the rate of photosynthesis and why?

Accepted Answer

It would decrease, because green light is mostly reflected, not absorbed, by chlorophyll.

Question 15

Which of the following is a correct summary of the ATP and NADPH requirements for the Calvin cycle to produce one net G3P molecule?

Accepted Answer

9 ATP and 6 NADPH

Question 16

A mutation causes a plant to lack functional ATP synthase in its thylakoid membranes. Which process would be directly affected?

Accepted Answer

Synthesis of ATP during the light reactions

Question 17

Which of the following best explains why the inner mitochondrial membrane is highly folded?

Accepted Answer

To increase the surface area for electron transport chains and ATP synthase complexes

Question 18

Which of the following is an example of a redox reaction in cellular respiration?

Accepted Answer

The transfer of electrons from NADH to the electron transport chain

Question 19

If a cell's supply of NAD$$^+ is $$depleted, which process would be most immediately affected and why?

Accepted Answer

Glycolysis, because NAD$$^+ is $$required to accept electrons during the oxidation of glucose

Question 20

A patient is exposed to a chemical that specifically inhibits the enzyme rubisco. Which of the following would be the most immediate effect on photosynthesis?

Accepted Answer

The Calvin cycle would be unable to fix carbon dioxide, halting sugar production.

Cellular Respiration & Photosynthesis: Organelle Structure and Bioenergetics

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