Human Reproduction — BIOLOGY STD 12 Science — Question

Lianas are vascular plants rooted in the ground and maintain erectness of their stem by making use of other trees for support. They do not maintain direct relation with those trees. Discuss the type of association the lianas have with the trees.

Suryakant had banana plantation in his field. Quality of the fruit was excellent but the yield suffered due to infection of the plants by a virus. Suggest a fast and efficient method to get healthy and a large number of plants in the next generation without compromising on the existing quality. Justify the selection of your method.

In Snapdragon, A cross between true breeding red flower (RR) plants and true breeding white flower (rr) plants showed a Progeny of plants with all pink flowers.

1. The appearance of pink flowers is not known as blending. Why?
2. What is the phenomenon known as?

What is an ideal contraceptive? Write any five possible side effects of contraceptive measures.

How are transgenic animals used in chemical safety testing?

List the attributes that populations possess but not individuals.

What are the main factors on which the disease development in a plant depends?

Name the five key tools for accomplishing the tasks of recombinant DNA technology. Also mention the functions of each tool.

Name the functions of the following: (a) Corpus luteum (b) Endometrium (c) Acrosome (d) Sperm tail (e) Fimbriae