Question

The control center of cell is
A. Nucleus
B. Mitochondria
C. Nucleolus
D. Ribosome

Answer 1

It contains genetic material, DNA. Chromosomes are small structures, which are thread-like, which contain a chromosome. Gens are a genetic unit in animals, which aids in the legacy of characteristics between the generations (parents) (offspring).

Complete solution:
The nucleus controls and regulates the activities of the cell. It is the control center of the cell. It facilitates transcription and replication process. Nucleus is known as the brain of the cell. Nucleus contains the genetic material that is transferred to the next generation.
Mitochondria is the powerhouse of the cell.
Nucleolus is known as the site of ribosome biogenesis. In nucleolus, transcription and processing of ribosomal genes takes place. Its size depends on the level of ribosome produced.
Ribosomes are known as protein factories; they are the main site of protein synthesis.

So, the answer is option A. Nucleus

Additional information:
Nucleus is a membrane - bound organelle.
The components of nucleus are – a phospholipid bilayer membrane, nucleoplasm, Nucleolus and chromatin materials.
Nuclear envelope is made of phospholipids that form a lipid bilayer.
On the nuclear membrane some nuclear pores are present that helps substances like RNA, proteins etc. to enter and leave the cell.
In the inner layer of nuclear membrane fibrous lamina is present that helps in regulating gene expression. Fibrous lamina also regulates entering and exiting of cells.
Nucleus is separated from the rest of the cell by a nuclear membrane.

Note:
Generally, the eukaryotic cell consists of one nucleus.
Some eukaryotic cells lack nucleus and they are known as enucleate cells. For example: RBCs
Some eukaryotic cells are multinucleated, and have more than one nucleus. For example: Slime molds.
It is the main organelle to serve as the control core for cells and is the cell's DNA storage facility.
The nucleus is circular and dark by structure, with a nuclear membrane surrounding it. It is a porous membrane, which forms a wall between the cytoplasm and the nucleus, equivalent to a cell membrane.
There are small spherical bodies inside the nucleus known as nucleolus. The structure, called chromosomes, is otherwise important.