Biotechnology: Principles and Processes — BIOLOGY STD 12 Science — Question

What is innate immunity? How is it accomplished in a human body?

Anukool is a big businessman in Delhi, but belongs to a small village. He went to his village during Christmas holiday. He was very disturbed to see women still using cowdung's cakes to prepare food there. He decided to set up a biogas plant so that people can use gas obtained from it for cooking. The villagers were very thankful to Anukool for his valuable help.

1. What is biogas?
2. What are the uses of biogas?
3. Name some microorganisms involved in biogas production.
4. What are the values shown by Anukool?

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.

If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?

Two heterozygous parents are crossed. If the two loci are linked what would be the distribution of phenotypic features in F₁ generation for a dibybrid cross?

Read the following and answer any four questions from (i) to (v) given below:

Transgenic animals can serve as factories that in some cases, may produce large amount of proteins more efficiently. Transgenic mice have been engineered to express human antibodies by introducing large segment of human DNA encoding human immunoglobulin genes. In transgenic large animals such as cow or sheep proteins of pharmaceutical value can be produced in large quantities in milk which is later purified. Transgenesis can be used to alter many phenotypic properties including growth rate, fat composition, milk production, hair texture, etc.

1. The production of transgenic animals includes

1. Identification and separation of desired gene.
2. Combining the desired gene with appropriate vector.
3. Introduction of vector in cells, tissues or embryos.
4. All of these.

2. In transgenic animals, i.e., cow and sheep proteins of pharmaceutical value are produced in large quantities in the

1. Blood.
2. Accumulated fat.
3. Mammary glands.
4. None of these.

3. Mouse is mostly preferred animal for studies on gene transfer because.

1.  Short oestrous cycle.
2. Long gestation period.
3. Short generation time.
4. Production of one or two offspring per pregnancy.

1. Both (A) and (C)
2. Both (A) and (B)
3. Only D
4. Both (C) and (D).

4. Transgenic genes alter many phenotypic properties including:

1. Growth rate.
2. Fat composition.
3. Milk production.
4. All of these.

5. Assertion: Transgenic mice have been engineered to express human antibodies.

Reason: Large segment of human DNA encoding human immunoglobulin have been transferred to mice.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Justify the following statement in terms of ecosystem dynamics. “Nature tends to increase the gross primary productivity, while man tends to increase the net primary productivity”.

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

Write the full name of the word AIDS. By what name is the virus that causes this disease known? Explain the symptoms and prevention measures of AIDS disease. Draw a labelled diagram of the replication of the AIDS virus.

Trace the path of spermatozoa from the testes upto the ejaculatory duct only.

OR

Schematically represent and explain the events of spermatogenesis in humans.