Answer:
A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events such as famines, earthquakes, floods, fires, disease, and droughts or human activities such as specicide and human population planning.
Explanation:
The Calvin cycle is the cycle where in sugars are produced
in the chloroplast. Calvin cycle is also known as the Calvin-Benson cycle.
Calvin cycle has three stages this is fixation, reduction, and
regeneration. Calvin cycle is needed in
Photosynthesis.
I believe the answer is D.