Question

question 5
how would the carbon cycle be disrupted if many plants on earth died off?

a the amount of nitrogen in earth’s atmosphere would increase, releasing water vapor and causing earth’s temperature to become cooler.
b the amount of oxygen in earth’s atmosphere would increase, releasing water vapor and causing earth’s atmosphere to become cooler.
c the amount of water in earth’s atmosphere would decrease, trapping water vapor and causing earth’s atmosphere to become warmer.
d the amount of carbon dioxide in earth’s atmosphere would increase, trapping more heat and causing earth’s atmosphere to become warmer.

Explanation:

Plants perform photosynthesis, which takes in atmospheric carbon dioxide ($CO_2$) to produce organic matter and release oxygen. If most plants died, this $CO_2$ uptake would stop. Meanwhile, natural processes like animal respiration and decomposition would still release $CO_2$ into the atmosphere. This would cause atmospheric $CO_2$ levels to rise. As a greenhouse gas, excess $CO_2$ traps more heat in the atmosphere, leading to a warmer climate. The other options are incorrect because they focus on unrelated gases (nitrogen, oxygen) or water, which are not the primary disruptions to the carbon cycle from mass plant die-off.

Answer:

d. The amount of carbon dioxide in Earth's atmosphere would increase, trapping more heat and causing Earth's atmosphere to become warmer.