Which of the following are covered by a single membrane?

Lipid molecules in the cell are synthesized by:

$(i)$ Why is the cell called the structural and functional unit of life?
$(ii)$ Why is the plasma membrane called a selectively permeable membrane?
$(iii)$ Name the factor which decides the movement of water across the plasma membrane.

Which cell organelle is known as the 'kitchen of the cell'?

Give the chemical composition and functions of plasma membrane and cell wall. Differentiate between the two.

State whether the following statement is true or false:
The nucleus plays a central role in cellular reproduction.