Human Reproduction — BIOLOGY STD 12 Science — Question

Enumerate the differences between asexual and sexual reproduction. Describe the types of asexual reproduction exhibited by unicellular organisms.

1. State the objectives of animal breeding.
2. List the importance and limitations of inbreeding. How can the limitations be overcome?
3. Give an example of a new breed each of cattle and poultry.

A normal visioned woman, whose father is colour blind, marries a normal visioned man. What would be the probability of her (a) sons (b) daughters to be colour blind? Explain with the help of pedigree chart.

Peer pressure plays a negative role in triggering smoking habits in adolescents. As a school captain, list any two activities you would like to organise with the help of senior students of your school and any other two activities you would like your school authorities to organise for the students to tackle this problem. Explain how these activities will help in doing so.

How do parasites harm the host? Name the two categories of parasites and differentiate between them. Give an example for each.

A person in your colony has recently been diagnosed with AIDS. People/residents in the colony want him to leave the colony for the fear a spread of AIDS.

1. Write your view on the situation, giving reasons.
2. List the possible preventive measures that you would suggest to the residents of your locality in a meeting organised by you so that they understand the situation.
3. Write the symptoms and the causative agent of AIDS.

Represent diagrammatically the steps in amplification of a DNA segment. Who designed the process?

a. Describe the process of double fertilisation in angiosperms.
b. Trace the development of polyploidal cell that is formed after double fertilisation in a non-albuminous seed and albuminous seed.