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

Question 1

Which of the following best describes the overall chemical equation for oxygenic photosynthesis?

Accepted Answer

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

Question 2

What is the main function of the light-dependent reactions in photosynthesis?

Accepted Answer

To capture energy from sunlight and produce ATP and NADPH

Question 3

Which pigment is directly involved in converting light energy to chemical energy during photosynthesis?

Accepted Answer

Chlorophyll a

Question 4

Why do leaves change color in the fall, as shown in the image with colored leaves?

Accepted Answer

Chlorophyll breaks down, revealing other pigments such as carotenoids and anthocyanins

Question 5

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

Accepted Answer

It uses ATP and NADPH to convert $$CO_2$$ into G3P

Question 6

What is the role of ATP synthase in the chloroplast?

Accepted Answer

It synthesizes ATP using the proton gradient across the thylakoid membrane

Question 7

Which enzyme is responsible for carbon fixation in the Calvin cycle?

Accepted Answer

Rubisco

Question 8

Why is photorespiration considered wasteful for plants?

Accepted Answer

It consumes oxygen and releases fixed carbon as $$CO_2$$, reducing photosynthetic efficiency

Question 9

Which adaptation allows C4 plants to minimize photorespiration?

Accepted Answer

Spatial separation of initial $$CO_2$$ fixation and the Calvin cycle

Question 10

What is the main advantage of CAM photosynthesis in desert plants?

Accepted Answer

Stomata open at night to reduce water loss

Question 11

Which of the following best explains why the energy content of a photon is inversely proportional to its wavelength?

Accepted Answer

$$E = \frac{hc}{\lambda}$$, where $$E is $$energy, $$h is $$Planck's constant, $$c is $$the speed of light, and $$\lambda is $$wavelength

Question 12

Which process occurs in the thylakoid membrane and results in the production of oxygen?

Accepted Answer

Splitting of water during the light-dependent reactions

Question 13

A plant is exposed to intense sunlight but its stomata are closed due to drought. What is the most likely consequence?

Accepted Answer

Photorespiration increases, reducing photosynthetic efficiency

Question 14

Which of the following is NOT a direct product of the Calvin cycle?

Accepted Answer

Glucose

Question 15

What is the main function of carotenoids in photosynthesis?

Accepted Answer

They absorb light energy and protect against oxidative damage

Question 16

How many turns of the Calvin cycle are required to produce one molecule of glucose?

Accepted Answer

Six

Question 17

Which of the following best describes the difference between C3 and C4 photosynthesis?

Accepted Answer

C4 plants initially fix $$CO_2$$ into a four-carbon compound using PEP carboxylase

Question 18

Which structure within the chloroplast contains the enzymes for the Calvin cycle?

Accepted Answer

Stroma

Question 19

What is the primary reason C4 photosynthesis is advantageous in hot, dry climates?

Accepted Answer

It reduces photorespiration, conserving fixed carbon

Question 20

Which of the following is a correct sequence of events in the noncyclic electron flow of the light-dependent reactions?

Accepted Answer

Photon absorption by PSII, electron transport, ATP synthesis, electron transfer to PSI, NADPH formation

Photosynthesis: Mechanisms, Structures, and Adaptations

Study Guide - Practice Questions