Question

Unicellular organisms are capable of (i) independent existence (ii) performing the essential functions of life
(a)Only I
(b)Only II
(c)Both A and B
(d)None of the above

Answer 1

Hint: Cells are the smallest and the basic unit of life in all the known organisms consisting of several cell organelles each having a specific role.

Complete answer:
Unicellular organisms are known as single-celled organisms that consist of a single cell. They are capable of performing both the independent existence and perform all the life processes for their survival. For example Amoeba, Chlamydomonas, Bacteria, Yeast, etc. are the independent completely developed unicellular organisms that do not depend upon others for their basic requirements and perform all the functions and life processes to survive.

Additional Information: -The unicellular organisms are made of a single cell, and cells are called the fundamental structural and functional unit life.
-The cells are made up of cytoplasm which is present at the center and is enclosed by a cell wall or cell membrane.
-In the human brain, around 80 billion cells are present.
-They are of two types: prokaryotes and eukaryotes.
-The unicellular organisms having a complete structure of a cell ensure independent existence.
-Cells are also called as the building blocks life as it performs all the functions.
-The unicellular organisms do not require two parents for reproduction.
-Reproduction occurs by binary fission in a single cell giving rise to two daughter cells.
-The functions of life are nutrition and growth.
-With the presence of cells, these organisms can get food to provide the energy and substances required for growth.
So, the correct answer is ‘Both A and B'.

Note: Cells were first discovered by Robert Hooke in 1665. The cell theory was given by Schleiden and Schwann in 1839 and was extended by Virchow which states that all the organisms are made up of one or more cells and cells come from pre-existing cells. It is studied that cells emerged on earth about 3.5 billion years ago.