$$6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6$ + 6O_2$$

Question 1

Which of the following best describes the overall chemical reaction for photosynthesis in plants?

Accepted Answer

$$6CO_2 + 6H_2O + 	ext{light energy} ightarrow C_6H_{12}O_6$ + 6O_2$$

Question 2

Which of the following statements about autotrophs and heterotrophs is correct?

Accepted Answer

Autotrophs produce their own food from inorganic molecules, while heterotrophs must obtain organic molecules from other organisms.

Question 3

During the light-capturing reactions of photosynthesis, what is the main function of chlorophyll?

Accepted Answer

To absorb light energy and transfer it to electrons, initiating the electron transport chain.

Question 4

Which of the following is a product of the light-capturing reactions that is used in the Calvin cycle?

Accepted Answer

NADPH

Question 5

A scientist exposes a plant to light but provides no CO$$_2. $$Which of the following will occur?

Accepted Answer

Oxygen will be produced, but the Calvin cycle will not occur.

Question 6

Which pigment is primarily responsible for the green color of plants and is most abundant in chloroplasts?

Accepted Answer

Chlorophyll

Question 7

What is the role of accessory pigments such as carotenoids in photosynthesis?

Accepted Answer

They absorb wavelengths of light not absorbed by chlorophyll and protect chlorophyll from damage.

Question 8

Which of the following best explains why plants appear green to our eyes?

Accepted Answer

Chlorophyll reflects green wavelengths of light and absorbs other wavelengths.

Question 9

Which of the following statements about the Calvin cycle is correct?

Accepted Answer

It uses ATP and NADPH produced by the light reactions to reduce CO$$_2 to $$carbohydrates.

Question 10

A mutation prevents a plant from producing NADP$$^+. $$Which process would be directly affected?

Accepted Answer

The reduction of NADP$$^+ to $$NADPH during the light reactions.

Question 11

Which of the following best describes the relationship between the light-capturing reactions and the Calvin cycle?

Accepted Answer

The light-capturing reactions provide ATP and NADPH to drive the Calvin cycle.

Question 12

Which of the following is NOT a photosynthetic organism?

Accepted Answer

Houseflies

Question 13

Why does the absorption of a photon by chlorophyll result in the excitation of an electron?

Accepted Answer

The energy of the photon is transferred to an electron, raising it to a higher energy state.

Question 14

Which of the following wavelengths of light has the highest energy?

Accepted Answer

400 nm (violet)

Question 15

If a plant is exposed only to green light, what will most likely happen to its rate of photosynthesis?

Accepted Answer

It will decrease because chlorophyll reflects green light.

Question 16

Which of the following best explains why oxygen is produced during photosynthesis?

Accepted Answer

Oxygen is released when water molecules are split during the light reactions.

Question 17

Which of the following is a correct comparison between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis stores energy in carbohydrates, while cellular respiration releases energy from carbohydrates.

Question 18

Which structure within the chloroplast contains the pigments that absorb light for photosynthesis?

Accepted Answer

Thylakoid membrane

Question 19

A plant is genetically modified so that its stomata cannot open. What is the most likely consequence?

Accepted Answer

CO$$_2$$ cannot enter the leaf, so photosynthesis will decrease.

Question 20

Which of the following best describes the function of the Calvin cycle in photosynthesis?

Accepted Answer

It incorporates CO$$_2$$ into organic molecules using ATP and NADPH.

Photosynthesis: Mechanisms, Organisms, and Light Energy in General Biology

Study Guide - Practice Questions