Question

18. ASSERTION:

Organisms are made up of cells.

REASON: Cells are structural unit of living organisms. A cell keep its chemical. composition steady within its boundary.

a) Both assertion and reason are correct but the

reason is the correct explanation of the assertion.

b) The assertion and reason are correct but reason is not the correct explanation of the assertion. c) Assertion is true but the Reason is false.

d) The statement of the assertion is false but the

reason is true.​

Answer 1

Answer:

cell is the structural and functional unit, of all organisms that serve as a building block of all organisms (both unicellular and multicellular) and is capable of carrying out all life processes. All cells are delimited by plasmalemma/cell membrane, which is a biological membrane that separates the cell’s interior from surrounding and from other cells. Being selectively permeable layer, cell membrane allows the exchange of desired molecules only thereby maintaining the unique chemical composition of cell’s interior.

Answer 2

The correct option is a) Both assertion and reason are correct and Reason is the correct explanation of Assertion.

- The smallest unit of life is a cell and it can perform all living functions.

- Different elements of animals and plants are made up of cells.

- The functional and essential structural elements of life are known as cells.

- A single cell organism digests food, develops, breathes,excretes and reproduces.

- In multicellular organisms, the same functions are performed by group of cells which are grouped into organs and tissues.

- Cells are surrounded by a structure known as cell membrane.

- The cell membrane which is selectively permeable layer only allows exchange of desired molecules .

- Therefore, option a) is the correct option.