Question

an example of mitosis at work is a leaf
turning yellow.
growing.
taking in carbon dioxide.
performing photosynthesis.

Explanation:

Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus. It is crucial for growth and repair in multicellular organisms. A leaf growing involves the production of new cells through mitosis. A leaf turning yellow is usually due to the breakdown of chlorophyll (not cell - division related). Taking in carbon dioxide is a part of the process of photosynthesis (a metabolic process, not cell - division). Performing photosynthesis is a biochemical process (using light energy to convert carbon dioxide and water into glucose and oxygen, not related to cell - division).

Answer:

growing.