What is oxidized during the Krebs cycle?

Groups of organisms with low biotic potential, such as gray whales, that produce at most one offspring every other year a) are r-selected b) are k-selected c) are not subject to density-dependent limiting factors d) show the initial stages of the extinction process e) have escaped from the processes of natural selection and adaptation

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?

The importance of the mind as a part of the body is an example of: