Why is it important for cells to be able to take in nutrients and excrete (remove) waste
products?

so that our body won't contain all the bad waste and allow all the good nutrients to help out our body.

Cells require energy to power their biochemical processes such as transcription and translation processes the nutrients taken in by cells are broken down and the energy in these bonds is used to create ATP’s , the energy currency of the cells

Explanation:

this would be called the responsiveness