Why is there a need for varietal improvement?

How is mariculture different from aquaculture?

Mention two ways of obtaining fish.

The government was setting up a school in the village. In the panchayat,Vinod,who had just completed his class $X$,suggested that the children should be taught about different agricultural practices and the use of modern technology in them. The Sarpanch liked the idea and arranged for the same.
$(a)$ Children were taught that wheat cannot be grown in the kharif season. Why?
$(b)$ Mention the desirable agronomic character for cereals.
$(c)$ Do you support the suggestion to the Sarpanch? Mention any two values for which Vinod is worth admiration.

Poultry farming is undertaken to raise the following:
$(i)$ Egg production
$(ii)$ Feather production
$(iii)$ Chicken meat
$(iv)$ Milk production

$(a)$ Mention the harmful effects of infectious diseases on the health of cattle.
$(b)$ How can these diseases be controlled?