Respiration and Circulation — BIOLOGY STD 12 Science — Question

A group of scientists is working on creating transgenic cows to produce milk with medicinal properties. But there are adverse side effects seen on the cows due to this procedure. Their lifespan shortened; they became prone to diseases and died very early.

1. What do you mean by transgenic animals?
2. Should the scientists continue with the production of transgenic cows? Give reason.
3. Is there any law to regulate such acts?
4. What values did scientists lack?

During the explanation of the significance of several breeding techniques, teacher makes a statement about inbreeding depression and suggested a solution for it. Pallavi became very curious about knowing all this and asked certain questions to his teacher.

1. Why is breeding required?
2. What is the significance of improved variety?
3. What is interspecific hybridisation?
4. What values are shown by Pallavi as a science student?

Write notes on ex-situ conservation of biodiversity

Describe the histology of 'human testis'. Write a note on human sperm.

Give significance : Transgenic plants.

What is oogenesis? Give a brief account of oogenesis.

What is the significance of epididymis in male fertility?

Define totipotency of a cell. List the requirements, if the objective is to produce somaclones of a tomato plant on commercial scale.

Explain the structure of cerebrum. Structure of cerebrum

You have a friend whose parents are too indulgent in his/her daily affairs. They think him/her to be still young which makes him/her sad and is upset all the time. As he/she feels that the parents should give him/her opportunity to take independent decision on some issues.

1. Would you support your friend and why?
2. Write the characteristics of this age group.
3. List two curative measures.