Question

question 8 of 25
why do plants produce more carbon dioxide than oxygen during the night?
a. respiration can happen without sunlight, but photosynthesis cannot.
b. photosynthesis only produces carbon dioxide during the night.
c. respiration can only occur when there is no available sunlight.
d. respiration produces oxygen during the day and carbon dioxide at night.

Explanation:

Plants carry out respiration all the time (day and night), which consumes oxygen and produces carbon dioxide. Photosynthesis, on the other hand, requires sunlight. During the day, photosynthesis occurs (producing oxygen) along with respiration. At night, without sunlight, photosynthesis stops, but respiration continues. So, more carbon dioxide is produced (from respiration) than oxygen (since photosynthesis - which produces oxygen - isn't happening).

• Option A: Respiration occurs all the time (no sunlight needed), photosynthesis needs sunlight. This explains why at night (no sunlight), only respiration (producing \(CO_2\)) occurs (while during the day both processes occur).
• Option B: Photosynthesis produces oxygen (in the presence of sunlight) and consumes \(CO_2\), not the other way around.
• Option C: Respiration occurs all the time (with or without sunlight).
• Option D: Respiration always consumes oxygen and produces \(CO_2\) (day and night).

Answer:

A. Respiration can happen without sunlight, but photosynthesis cannot.