Define lipids.

Read the following statements on lipids and find out the correct set of statements:

(a) Lecithin found in the plasma membrane is a glycolipid.

(b) Saturated fatty acids possess one or more $\mathrm{C}=\mathrm{C}$ bonds.

(c) Gingelly oil has a lower melting point, and hence remains as oil in winter.

(d) Lipids are generally insoluble in water but soluble in some organic solvents.

(e) When a fatty acid is esterified with gIycerol, monoglycerides are formed.

Choose the correct answer from the options given below:

What is the basic difference between saturated and unsaturated fatty acid?

Identify the following structure.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

Rancidity of fats is