Nucleus

Question 1: Who discovered the nucleus?

Answer:

Nucleus as a cell organelle was first discovered by Robert Brown as early as 1831. 

Question 2: What is the function of nucleus?

Answer:

The nucleus is known as the controller of a cell and its metabolic activities. If the nucleus is removed from a cell, the protoplasm will dry up and dies ultimately and the nucleus is responsible for the cell cycle, it regulates it.

Question 3: What is the position of the nucleus inside a cell?

Answer:

It is found in the region of maximum metabolic activity in the cytoplasm. Commonly, it is situated in the geometric center of the cell. The nucleus is peripheral in fat-storing cells, in plant cells due to the development of a large central vacuole, and basal in glandular cells. In Spirogyra, it is suspended in the central vacuole by cytoplasmic strands.

Question 4: Define the structure of the nucleus.

Answer:

A typical interphase nucleus is 5-25 mm in diameter and is differentiated into five parts-nuclear envelop, nucleoplasm, nuclear matrix, chromatin, and nucleolus.

Question 5: What do you mean by nucleolus?

Answer:

A nucleolus is a naked, round, or slightly irregular structure that is attached to the chromatin at a specific region called the nuclear organizer region (NOR). About 1-4 nucleoli are found commonly in a nucleus. A covering membrane is absent around the nucleolus.

The cell is the basic structural and functional unit of living organisms. In biology, the cell has the same central position as that of an atom in the physical sciences. The bodies of living organisms are made up of microscopic units called cells. Cells have evolved a variety of different lifestyles. Many organisms, such as bacteria (both archaebacteria and eubacteria), protozoa(e.g., amoeba), and yeasts consist of single cells (called unicellular organisms) that have the ability to perform a function like self-replication. More complex organisms, called multicellular organisms, those consists of collections of cells that perform particular functions.

Term cell was discovered by Robert Hook in his book Micrographia. The size of the cell is 10-16 micrometers. The shape of the cell may be polygonal, disc-like amoebic, thread-like, cuboid or irregular, oval, hexagonal, circular, branched, elongated, etc. The cells are too small to be seen with naked eyes. So, it is studied with the help of microscopes.