Reproduction in animals ..

a. Layers are the hens which are raised for production of eggs. These are the varieties of hens which lay good quality eggs in large numbers.

Broilers are the hens which are raised for met production. These are the varieties of poultry from which high quality meat is obtained in high amounts.

b. Hens lay fertilized eggs only when they have mated with the rooster. In most of the cases in poultry farms, the hens are not allowed to mate with rooster so, the eggs they lay are unfertilized.

c. Fertilized eggs are obtained after the hen has mated with the rooster, while unfertilized are obtained without mating.

d. We cannot predict whether the egg available in the shops are fertilized or not but they are generally unfertilized. However, both are safe for consumption.  

e. Yes, we can consume fertilised eggs unless that egg has been incubated, because upon incubating the embryo starts developing inside the egg.  

f. There is no nutritional difference among fertilized and unfertilized eggs. The fresh has lots of protein content than the egg kept for few days.