What are the structures in your kidneys that work to filter excess salt and water from your blood

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

What must be true for natural selection to heppen

Describe two recent or ongoing space missions.