Question

……. is the basic unit of life.
A) Cell
B) Tissue
C) System
D) Organism

Answer 1

Hint: It is the structural, biological or functional unit of all organisms. Study of it is called cytology. It varies in different species. It consists of several organelles also.

Complete answer:
Let’s discuss the given options and find the correct answer.
>Cell is a basic structural molecule of life. It is also called a building block. At first cells were discovered by the scientist Robert Hooke. It is of two types: Prokaryotic and Eukaryotic. Eukaryotic cells are present in higher organisms having a true nucleus while prokaryotic cells do not contain a true nucleus.
>Collection of cells is known as tissue. It comes from French word “tissu”. Study of animal tissue is called histology and when it comes in contact with any disease is called histopathology. In plants, tissues are of two types- Meristematic tissue and Permanent tissue.
>When a group of organs work together it is called a System. There are many systems included in biology. Such are- immune system, lymph system, circulatory system etc. As an example, the nervous system is related to the brain, respiratory system is related to respiration etc.
>An organism is any life form present on earth. It may be dog, cat, human and all. Every living creature comes under this.

Hence, option A Cell is the correct answer.

Note:Cells are the building blocks of life. No organisms can produce without a cell. In many organisms, it is surrounded by the membranes. Here the genetic material is DNA (Deoxyribonucleic acid) or RNA (ribonucleic acid).