Questions: What is that large organelle stained purple in the middle of the cell that we see? Endoplasmic Reticulum Mitochondria Centrioles Nucleus

The answer is the fourth one (D): Nucleus.

Explanation for each option:

• Endoplasmic Reticulum: This organelle is involved in protein and lipid synthesis and is not typically visible as a large, distinct structure in stained cheek cells under a microscope.

• Mitochondria: These are the powerhouses of the cell, responsible for energy production. While they can be stained, they are not usually the largest or most prominent organelle visible in a simple cheek cell stain.

• Centrioles: These are involved in cell division and are not typically visible as a large organelle in stained cheek cells.

• Nucleus: The nucleus is the large organelle that contains the cell's genetic material. It is often stained purple in microscope slides, making it the most prominent feature in the center of the cell.

In summary, the large organelle stained purple in the middle of the cheek cell is the nucleus.