Who observed the cell for the first time and when?

Lipid molecules in the cell are synthesized by

Define and explain the importance of the following phenomena in living cells:
$(a)$ Diffusion
$(b)$ Osmosis.

$(a)$ Name the organelle which provides turgidity and rigidity to the plant cell. Name any two substances which are present in it.
$(b)$ How are they useful in unicellular organisms?

Silver nitrate solution is used to study which of the following cell organelles?

$(a)$ What role do vacuoles play in a typical plant cell?
$(b)$ What will happen if the Golgi apparatus is removed from the cell?
$(c)$ Why is the inner membrane of mitochondria deeply folded?