Question

Which of the following is immortal?
A. Germ cells
B. Pituitary cells
C. Brain cells
D. All of the above

Answer 1

Each and every living organism are composed of the cells which are the basic structural, functional as well as the biological units. The different types of activities required by the organism are carried out by these units. Organisms may be single celled or multicellular in nature.

Complete answer:
The cells consist of cytoplasm which is enclosed by a delimiting membrane called the plasma membrane. It contains several organelles that are specialized for performing different function or biological processes. All cells except the red blood cells contain the nucleus which acts as the controlling center of the cell.
The living organism is made up of several different types of cells. The different body cells can be of two types such as somatic cells and germ cells. The somatic cells are the cells that make up the body of an organism in the multicellular organism. The somatic cells undergo through the normal process of wear and tear and apoptosis. The cells are subjected to the process of programmed cell death and it leads to the removal of old cells and formation of new cells.
Germ cells are the cells that give rise to the reproductive cells in the sexually reproducing animals. The reproducing cells are also known as gametes. The male gametes or male reproductive cell is known as sperm and the female gamete is known as the ovum. The germ cells produce gametes and it undergoes the process of mitosis as well as meiosis. The fusion of the male and female gamete give rise to the zygote or the embryo which develops into an adult and again the off spring produces germ cell based on its sex. The zygote does serve as the first cell of the next generation hence the germ cells are considered as immortal cells.
The cells of the pituitary and the brain cells are considered as somatic cells as they undergo cell death and die in due course.

Hence, the correct answer is option (A).

Note: The living organisms are made up of different types of cells such as the somatic and the germinal cells. The somatic cells are cells that are exposed to normal wear and tear and they die in the normal course of time. The germ cells give rise to the gametes such as the sperm and ovum. The sperm and ovum fuse to form the zygote which further gives rise to the offspring. Thus, the germ cells are considered as immortal cells.