1.(a) Mention any four strategies adopted by flowering plants to prevent self-pollination.
(b) Define the term emasculation.

2.The immune system of a person is not making discrimination between the molecules of “self” and “non self”.How will this situation affect his body? Name any one pathological disorder which results due to this situation.What happens to nerve cells in multiple sclerosis?

3.When a snapdragon plant bearing pink colour flower was selfed, it was found that, 69 plants were having red coloured flowers. What would be the number of plants bearing pink flower and white flower. Show with the help of Punnett square. Identity the principle of inheritance involved in this experiment

4.(a) Explain any two defence mechanisms plants have evolved against their predators.
(b) How does predation differ from parasitism ?

5.Why do lepidopterans die when they feed on Bt cotton plant ? Explain how does it happen.

6.Write the differences between wind pollinated and insect pollinated flowers. Give one example for each type of pollination.

7.Enumerate the role of microbes as biofertilizers in organic farming.

8.Give reason : - (a) A liverwort plant is unable to complete its life cycle in a dry environment.
(b) Number of male gametes produced is much more than the female gametes produced.
(c) Organisms exhibiting external fertilization show great synchrony between the sexes and release a large number of gametes into surrounding medium.

9.CryIAbis introduced in a plant to prevent infestation by corn borer.
(a) What is the resultant plant referred as?
(b) Summarize the action of the gene introduced

10.Give some adaptations of desert plants to survive the heat.

11.What is gene therapy? Illustrate using the example of adenosine deaminase (ADA) deficiency.

12.(a) Write the desirable characters a farmer looks for in his sugarcane crop.
(b) How did plant breeding techniques help north Indian farmers to develop cane with desired characters?

13.Drinking water problem in our urban areas is caused mainly because we fail to protect our water bodies. Explain how accelerated eutrophication chokes our water bodies to Death.

14.Draw a labelled diagram of the embryonic stage that gets implanted in the human uterus. State the functions of the two parts labelled.

15.With the help of an example, explain how Bacillus thuringiensis has helped in developing pest resistance in crops.

16.How are 'competent' bacteria transformed with recombinant DNA ? Explain.

17.What is apomixis? Describe its importance?

18.A criminal blew himself up in a local market when was chased by cops. His face was beyond recognition. Suggest and describe a modern technique that can help establish his identity.

19.Explain the cause of chromosomal disorders in humans. Describe the effect of such disorders with the help of an example each involving (i) autosomes, and (ii) sex chromosomes.

20.Draw a flow chart to depict the multiplication of an HIV virus in a host cell.