Sexual reproduction increases genetic diversity, which is important for a population’s adaptability and survival in changing environments.

A human sperm cell contains 22 autosomes plus an X or a Y chromosome.

In mitochondria, the electron transport chain pumps protons to the mitochrondrial matrix.

When respiration is not possible, yeast cells can obtain energy by alcohol fermentation. Which of the following best describe the main byproducts of this two-step process? 

Photosystem I receives electrons from the electron transport chain that originates in Photosystem II.

The process by which most unicellular organisms, like bacteria, divide is known as ______. 

After three turns of the Calvin Cycle, 2 molecules of glyceraldehyde 3-phosphate are converted into 1 molecule of glucose. 

The majority of CO₂ produced from cellular respiration is released during the citric acid cycle.

Unicellular organisms, like bacteria, only use cell division for growth and development. 

When does substrate-level phosphorylation occur during cellular respiration?