What is the largest organelle in an animal cell?

The largest organelle in an animal cell is the nucleus.

The nucleus acts as the control center of the cell. It stores the cell’s genetic material (DNA) and helps in controlling important activities such as growth, metabolism, and reproduction. The nucleus is surrounded by a double-layered membrane called the nuclear envelope, which protects the DNA and controls what enters or exits the nucleus.

Although other organelles like the endoplasmic reticulum and mitochondria are also important, the nucleus is the biggest and most easily visible organelle when viewed under a microscope.

Why Is the Nucleus Important?
Without the nucleus, the cell would not be able to function properly because it wouldn’t have instructions (from DNA) to make proteins or to divide and grow. That’s why the nucleus is often called the “brain of the cell.”