Human Reproduction — BIOLOGY STD 12 Science — Question

Scientists have succeeded in recovering healthy sugarcane plants from a diseased one.

1. Name the part of the plant used as explant by the scientists.
2. Describe the procedure the scientists followed to recover the healthy plants.
3. Name this technology used for crop improvement.

Name the pest that destroys the cotton bolls. Explain the role of Bacillus thuringiensis in protecting the cotton crop against the pest to increase the yield.

1. A parasite has to adapt to be able to live in the host. Write the various parasitic adaptations.
2. Mention an adaptive feature exhibited in brood parasitism in Koel and Crow.

How do accessory glands in man help in semen formation and reproduction process?

The below image shows is the headquarter of Eli Lilly company. Eli lily is one of the first pharmaceutical companies to produce human insulin using RDT technology by cell-based fermentation method.

i. How did Eli Lilly synthesize human insulin?
ii. Mention one difference between this insulin and the one produce by the human pancreas.

(i) EcoRI has played a very important role in recombinant DNA technology.
(a) Explain the naming convention of Eco RI.
(b) Write the name of the recognition site and cleavage site of this restriction enzyme.
(ii) What is the longitudinal extension of DNA produced by these restriction enzymes called? Describe their role in the formation of r-DNA.

Find out from newspapers and popular science articles any new fossil discoveries or controversies about evolution.

Questions 1-3 are based on the following diagram. Read the questions and fill the blank spaces:

1. Each level of a pyramid represents a trophic level. With reference to the grazing food web, name an organism at the first trophic level. ______ (a) ______. Two organisms at the second trophic level ______(b)______ Two organisms at the third trophic level ______ (c) ______.
2. With reference to a pyramid of energy, why is each trophic level reduced in size?
3. Why is there a limited number of trophic levels?

Why is a recombinant protein so called? How can it be harvested on a large scale? Write two precautions to maintain a higher yield.

Name the source of streptokinase. How does this bioactive molecule function in our body?