Reproductive Health — BIOLOGY STD 12 Science — Question

Both Haemophilia and Thalassemia are blood related disorders in humans. Write their causes and the difference between the two. Name the category of genetic disorder they both come under.

What are biofertilizers? Name the two elements which are made available by them.

Seeing a crowd of students in one corner of the school, the principal rushed to see the matter and found some children beating and chasing a small lizard. On seeing the principal, all the children fled to their classes except Alok who requested the principal to arrange for some medical assistance for the injured animal. The principal rewarded Alok for his attitude to save guard our biodiversity.

1. Mention the factors resulting in loss of biodiversity
2. Was Alok an indisciplined boy, who did not run to the class on seeing the principal? What values does the act promote?

What is the importance of Species-Area Relationship ?

What is eltonian pyramid?

Why is predation required in a community of different organisms?

Distinguish between gross primary productivity and net primary productivity.

Three water samples namely river water, untreated sewage water and secondary effluent discharged from a sewage treatment plant were subjected to BOD test. The samples were labelled A, B and C; but the laboratory attendant did not note which was which. The BOD values of the three samples A, B and C were recorded as 20mg/L, 8mg/L and 400mg/L, respectively. Which sample of the water is most polluted? Can you assign the correct label to each assuming the river water is relatively clean?

Name and explain the technique that helps in separation of DNA fragments for recombinant DNA technology experiments. How can these separated DNA fragments be visualised?

OR

1. Name the technique used for the separation of DNA fragments.
2. Write the type of matrix used in this technique.
3. How is the separated DNA visualised and extracted for use in recombinant DNA technology?

Mention any two human diseases caused by roundworms. Name their causative agents and their mode of transmission into the human body.