Q: Which of the following best represents the overall equation for photosynthesis in plants?

$$6 \text{CO}_2 + 6 \text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_{12}\text{O}_6 + 6 \text{O}_2$$

Question 1

Which of the following best represents the overall equation for photosynthesis in plants?

Accepted Answer

$$6 	ext{CO}_2 + 6 	ext{H}_2	ext{O} + 	ext{light energy} ightarrow 	ext{C}_6	ext{H}_{12}	ext{O}_6 + 6 	ext{O}_2$$

Question 2

What is the primary function of pigments such as chlorophyll a in photosynthesis?

Accepted Answer

To absorb photons and excite electrons for use in the light reactions

Question 3

Which of the following statements about the light reactions of photosynthesis is correct?

Accepted Answer

They produce ATP and NADPH, which are used in the Calvin cycle

Question 4

Why do leaves appear green to the human eye?

Accepted Answer

Chlorophyll reflects green wavelengths of light

Question 5

Which of the following best describes the role of water in the light reactions of photosynthesis?

Accepted Answer

Water is split to provide electrons and protons, releasing oxygen as a byproduct

Question 6

A plant is exposed only to green light. What is the most likely outcome for its rate of photosynthesis?

Accepted Answer

The rate of photosynthesis will decrease because chlorophyll reflects green light

Question 7

Which of the following is a product of the Calvin cycle?

Accepted Answer

G3P (glyceraldehyde-3-phosphate)

Question 8

What is the main purpose of accessory pigments in photosynthetic organisms?

Accepted Answer

To absorb wavelengths of light that chlorophyll a cannot absorb

Question 9

Which of the following best explains why blacktop (asphalt) gets hotter than white concrete on a sunny day?

Accepted Answer

Blacktop absorbs more wavelengths of light, converting them to heat

Question 10

During the light reactions, what is the immediate fate of the electrons excited by photons in the first photosystem?

Accepted Answer

They are transferred to the electron transport chain

Question 11

Which of the following is true about the energy of light with a wavelength of 480 nm compared to 700 nm?

Accepted Answer

480 nm light has more energy than 700 nm light

Question 12

In the Calvin cycle, what is the role of ATP and NADPH?

Accepted Answer

They provide energy and reducing power to convert CO$$_2$$ into G3P

Question 13

Which of the following is a correct sequence of events in the light reactions?

Accepted Answer

Photon absorption, water splitting, electron transport, ATP and NADPH formation

Question 14

A mutation prevents a plant from producing NADP+. What is the most immediate effect on photosynthesis?

Accepted Answer

The plant cannot produce NADPH, halting the Calvin cycle

Question 15

Which structure in the chloroplast is the site of the light reactions?

Accepted Answer

Thylakoid membrane

Question 16

Why do leaves change color in the fall?

Accepted Answer

Chlorophyll breaks down, revealing accessory pigments

Question 17

Which of the following is an example of a photosynthetic autotroph?

Accepted Answer

Cyanobacteria

Question 18

If the stomata of a leaf are closed, which process is directly affected?

Accepted Answer

Gas exchange of CO$$_2$$ and O$$_2$$

Question 19

Which of the following best describes the fate of oxygen atoms from water molecules during photosynthesis?

Accepted Answer

They are released as O$$_2$$ gas

Question 20

A scientist exposes a plant to only red light and measures its rate of photosynthesis. What is the most likely result compared to exposure to white light?

Accepted Answer

The rate will decrease because not all pigments absorb red light efficiently

Photosynthesis: Principles, Mechanisms, and Biological Significance

Study Guide - Practice Questions

Study Guide - Flashcards