Biotechnology and its Applications — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
IUCN maintains a Red Data Book or Red List which is a catalogue of taxa facing risk of extinction. The IUCN Red List (2004) documents the extinction of 784 species in the last 500 years. Some examples of recent extinctions include the dodo, quagga, thylacine and Steller's sea cow. The last twenty years alone have witnessed the disappearance of 27 species. Red List has eight categories of species.

1. Dodo, an extinct taxon, belongs to which country?

1. Mauritius
2. Africa
3. Australia
4. Russia

2. To which of the following categories of IUCN, Berberis nilghiriensis belongs?

1. Extinct.
2. Extinct in wild.
3. Endangered.
4. Critically endangered.

3. Steller's sea cow and passenger pigeon became extinct due to:

1. Alien species invasion.
2. Over-exploitation.
3. Coextinctions.
4. Intensive agriculture.

4. Bali, Javan and Caspian are:

1. Species of tiger.
2. Species of cheetah.
3. Subspecies of cheetah.
4. Subspecies of tiger.

5. Select the correct term for the following definitions (i, ii, iii, iv).

• The taxon is liable to become extinct if not allowed to realise its full biotic potential by providing protection from exotic species/ human exploitation/habitat deterioration/depletion of food.
• The taxon has been completely eliminated or died out from earth, e.g., Dodo.
• The taxon is facing a high risk of extinction in the wild in the near future due to decrease in its habitat, excessive predation or poaching.
• They are species with naturally small populations, either localised or thinly scattered, which are always at risk from pests/ pathogens/ predators/ exotic species.

	(i)	(ii)	(iii)	(iv)
(a)	Threatened	Extinct	Endangered	Rare
(b)	Endangered	Extinct	Threatened	Rare
(c)	Extinct	Rare	Threatened	Endangered
(d)	Threatened	Extinct	Rare	Endangered

Read the following and answer any four questions from 7(i) to 7(v) given below:

The vectors are DNA molecules that can carry a foreign DNA segment and replicate inside the host cell. Vectors may be plasmids, bacteriophages (viruses that attack bacteria), cosmids, yeast artificial chromosomes (YACs), Bacterial artificial chromosomes (BACs) and viruses. The most widely used, versatile, easily manipulated vector pBR 322 is an ideal plasmid vector. Features that are required to facilitate cloning into a vector includes origin of replication (Ori) which is a specific sequence of DNA bases responsible for initiating replication, selectable marker genes and cloning sites

1. Pin pBR 322 denotes that it is a:

1. plasmid
2. prokaryote
3. protist
4. plant cell.

2. Ori is a specific DNA sequence that help in.

1. Attachment of primers.
2. Initiation of replication.
3. Extension of DNA base.
4. Initiation of denaturation.

3. A and B shown in the figure respectively indicates:

1. Pvu II and Cla I.
2. ROP and Sal I.
3. amp^R and tet^R.
4. tet^R and amp^R.

4. Selectable markers in vector,

1. Are responsible for replication.
2. Help in selecting transformants from non-transform ants.
3. Code for proteins involved in the replicating plasmids.
4. Contain unique recognition sites.

5.  Plasmid vectors are:

1. dsDNA molecule
2. Extra-chromosomal
3. Present in bacteria and yeast
4. All of these.

Write a short note on transcription unit.### Explain : Transcription unit

Read the following and answer any four questions from (i) to (v) given below:
The foundations of recombinant DNA (rDNA) were laid by the discovery of restriction enzymes. These enzymes are present in many bacterias where they function as a part of their defense mechanism called the Restriction Modification system (RM system). Molecular basis of this system was explained first by Werner Arber in 1962. The Restriction Modification system consists of two components:

• A restriction enzyme (called restriction endonuclease) identifies the introduced foreign DNA and cuts it into pieces.
• The second component is a modification enzyme (methylase) that adds a methyl group to DNA at specific site to protect it from the restriction enzyme cleavage.

1. Restriction endonucleases are enzymes present in ________ where they function as a part of _______ mechanism.

1. (i) bacteria (ii) digestive
2. (i) protists (ii) transcription
3. (i) plant cells (ii) replication
4. (i) prokaryotes (ii) defence

2. Which of the following statements regarding modification enzyme is correct?

1. It adds methyl group to one or two bases usually within the host DNA sequence to protect it from the restriction enzyme.
2. It adds ethyl group to one or two bases usually within the sequence recognised by the restriction enzymes.
3. It adds methyl group to only one of bases within the foreign DNA sequence that is recognised by the restriction enzymes.
4. None of these.

3. Which of the following is a type II restriction enzyme?

1. Alu I
2. EcoR I
3. BamH I
4. All of these.

4. Which of the following is the first discovered restriction endonuclease?

1. Sal I
2. EcoR I
3. Hind II
4. EcoR II

5. Components of Restriction Modification System include?

1. Restriction enzyme.
2. Modification enzyme.
3. Lysing enzyme.
4. Both (a) and (b).

Explain population attributes.

Explain: Acquired Immunity.

Describe: Genetic engineered insulin

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

Medical termination of pregnancy is termination of pregnancy before the fetus become viable. To reduce the incidence of illegal abortion and consequent maternal mortality, MTP Amendment Act, 2017 was enacted by the government of India. About 40-50 million MTPs are done in a year all over the world.

1. Abortion can be safely done for about ______ weeks of pregnancy.

1. 4
2. 12
3. 8-10
4. 15-18

2. How is MTP helpful in decreasing human population?

1. By aborting normal female fetus.
2. By aborting normal female fetus.
3. By getting rid of unwanted pregnancies.
4. None of these.

3. Select an incorrect statement for MTP.

1. Second trimester abortions are more risky than first trimester.
2. It is being misused to abort normal female fetus.
3. It helps to get rid of unwanted pregnancies.
4. Child detected with congenital heart disease cannot be aborted.

4. MTP was legalised by Government of India in:

1. 1971
2. 1982
3. 1973
4. 1991

5. Assertion: MTPs are safe during first trimester of pregnancy.

Reason: After first trimester, fetus become intimately associated with the maternal tissues.

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.

What is the mechanism by which the AIDS virus causes deficiency of immune system of the infected person?