Which of the following is not an extension of a cell?Group of answer choicesmicrovilliflagellacilianucleus

To determine which option is not an extension of a cell, let's analyze each of the choices:

1. Microvilli: These are small, finger-like projections on the surface of some cells, mainly found in the intestines, that increase surface area for absorption.

2. Flagella: These are long, whip-like structures that protrude from the cell body of certain cells (like sperm cells) and are used for movement.

3. Cilia: These are short, hair-like structures on the surface of some cells that help in movement or in moving fluids across the cell surface.

4. Nucleus: This is the membrane-bound organelle that contains the cell's genetic material and controls its activities. It is not a protruding structure or an extension.

Conclusion:

The option that is not an extension of a cell is nucleus.