Pomphret,mackerel,tuna,sardines and Bombay duck are the popular freshwater fish varieties.

Unpredictable monsoon,droughts,and low rainfall are adversely affecting Indian agriculture.
$(a)$ Mention any two initiatives that have been adopted to increase the availability of water for agricultural purposes.
$(b)$ State two advantages of making check dams.
$(c)$ Briefly describe the canal and river lift systems of irrigation.

$(a)$ What is composite fish culture system?
$(b)$ Mention one merit and one demerit of this system.

In agricultural practices,higher input gives higher yield. Discuss how?

Ria was studying about $DNA$ in her textbook,learning that $DNA$ molecules are responsible for constructing and organizing cells and are present as part of chromatin material in the nucleus to transfer hereditary information. Ria was confused about how she could know if she possesses all the hereditary information from her parents. Her mother explained that through their hair or cells,the $DNA$ of parents and a child can be matched.
$(a)$ What kind of qualities are shown by Ria's mother?
$(b)$ In which part of a cell is $DNA$ found? State its function.

$(i)$ List three factors on which cultivation practices and crop yield depend.
$(ii)$ Name three stages involved in farming practices.