Control and Co-ordination — BIOLOGY STD 12 Science — Question

Distinguish between the following:
Hibernation and Aestivation

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.

How does spleen act as lymphoid organ? Explain.

Sketch and label seminiferous tubule as seen in the T.S. of testis.

Name the enzyme produced by Streptococcus bacterium. Explain its importance inmedical sciences.

Give reasons for the following:

1. The human testes are located outside the abdominal cavity.
2. Some organisms like honey-bees are called parthenogenetic animals.

Mention one application for each of the following:

1. Passive immunisation.
2. Antihistamine.
3. Colostrum.
4. Cytokinin-barrier.

How many microspore mother cells would be required to produce one hundred pollen grains in a pollen sac? And why?

List four advantages that a symbiotic mycorrhizal association provides to the host plant.

Fill in the blanks and complete the chart.

GMO	Purpose
(i) Bt cotton	———–
(ii) ———-	Delay the softening of tomato during ripening
(iii) Golden rice	———–
(iv) Holstein cow	———–