Sterols are composed of a steroid nucleus and . . . . . . .

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 $C=C$ bonds.
$(c)$ Gingely oil has a lower melting point,hence remains as oil in winter.
$(d)$ Lipids are generally insoluble in water but soluble in some organic solvents.
$(e)$ When fatty acid is esterified with glycerol,monoglycerides are formed.
Choose the correct answer from the options given below:

Identify the given structures $P$ and $Q$.

Which groups are present in the structures of sterol and sterone,respectively?

Which of the following is a group of saturated long-chain fatty acids?

How many molecules of long-chain fatty acids are present in the structure of wax?