Human Reproduction — BIOLOGY STD 12 Science — Question

Which methodology is used while sequencing the total DNA from a cell? Explain it in detail.

Draw the structure of HIV virus of AIDS and give its transmission, symptoms and treatment.
OR
Draw a labeled picture of HIV. Describe its structure.

Describe the ill-effects of alcohol on different parts of a body of an individual.

Describe the main ideas behind the biological control of pests and diseases.

Answer the following questions:
Name the hormones secreted and write their functions:

1. By corpus luteum and placenta (any two) .
2. During Follicular phase and parturition.

1. A pea plant bearing axial flowers is crossed with a pea plant bearing terminal flowers. The cross is carried out to find the genotype of the pea plant bearing axial flowers. Work out the cross to show the conclusions you arrive at.
2. State the Mendel’s law of inheritance that is universally acceptable.

Arun visited his grandfather's farm and noticed that one of the workers was introducing earthworms in the soil. He quickly rushed to his grandfather and asked him the reason. His grandfather explained him the advantages of earthworm in soil improvement.

1. Why are earthworms also known as detritivores?
2. Explain fragmentation.
3. Name the steps in the process of decomposition.
4. What values are shown by Arun?

Answer the following questions:
Why is banana called a parthenocarpic fruit? Would you call banana a true fruit? Give reason in support of your answer.

Which element is responsible for causing soil salinity? At what concentration does the soil become saline?