Human Reproduction — BIOLOGY STD 12 Science — Question

If your family owned a dairy farm, what measures would you undertake to improve the quality and quantity of milk production?

Expand LAB. Mention two benefits LAB provides.

Kishor visited his village and saw some trees on the boundary of the agricultural field. He thought that these are for partioning the land and discussed the matter with his grandfather. His grandfather explained him the utility of trees to the farmers and the farmlands.

1. What are the benefits these trees impart to the farmland?
2. What are such trees called?

Two types of aquatic organisms in a lake show specific growth patterns as shown below, in a brief period of time. The lake is adjacent to an agricultural land extensively supplied with fertilisers.

Answer the questions based on the facts given above:

1. Name the organisms depicting the patterns A and B.
2. State the reason for the growth pattern seen in A.
3. Write the effects of the growth patterns seen above.

In a maternity clinic, for some reasons the authorities are not able to hand over the two new-borns to their respective real parents. Name and describe the technique that you would suggest to sort out the matter.

What is the association between the bumblebee and its favourite orchid Ophrys? How would extinction or change of one affect the other?

1. What is primary productivity? Why does it vary in different types of eco - systems?
2. State the relation between gross and net primary productivity.

What is genetic code? How did genetic code came into existence ?

Explain the mechanism of ‘sex determination’ in birds. How does it differ from that of human beings?

How do homogametes differ from heterogametes? Give an example of an organism for each of the two kinds.