Human Reproduction — BIOLOGY STD 12 Science — Question

What is point mutation? Give one example.

Explain the difference between commensalism and mutualism types of interactions, with the help of a suitable example of each.

A schematic representation of Polymerase Chain Reaction (PCR) up to the extension stage is given below. Give answers of the following questions.

1. Name the process A.
2. Identify B.
3. Identify C and mention its importance in PCR.

Given below is a figure of a biogas plant.

1. Identify A and justify its floating nature.
2. Identify the products B and C and discuss their significance.

Refer to the diagram given below and answer the questions that follow.

1. The parasite reproduces in human host by which method?
2. The sexual stages of parasite are referred to as?
3. Where does the fertilisation and development of parasite takes place in mosquito body?
4. What are sporozoites?
5. What is the cause of cycles of fever during malaria?

A cross is made between different homozygous pea plants for contrasting flower positions.

1. Find out the position of flowers in F₁ generation on the basis of genotypes.
2. Work out the cross upto F₂ generation.
3. Compute the relative fraction of various genotypes in the F₂ generation?

a. Given below is the stepwise schematic representation of the process of electrophoresis. Identify the alphabets representing (i) Anode end (ii) smallest/lightest DNA strand in the matrix (iii) Agarose gel

b. What is elution? State the importance of elution in this process.

List the salient features of genetic code###Give important feature of genetic code###Write any six main teatares of genetic code

What is the chromosomal basis of Turner’s syndrome? Mention the sex and any three symptoms of this disorder.

Why are angiosperm anthers called dithecous? Describe the structure of its microsporangium.