Inheritance and Variation — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
DNA fingerprinting is a technique of determining nucleotide sequences of certain areas of DNA which are unique to each individual. Each person has a unique DNA fingerprint. Each fingerprint is the same for every cell, tissue and organ of a person. DNA fingerprinting is the basis of paternity testing in case of disputes.

1. The technique developed to identify a person with the help of DNA restriction analysis is known as.

1. DNA profiting
2. DNA fingerprinting
3. RFLP
4. Both (a) and (b).

2. For DNA fingerprinting, DNA is obtained from.

1. Blood
2. Hair root cells
3. Semen
4. All of these

3. During DNA fingerprinting, the radioactive probes.

1. Hybridise with DNA sample to form double stranded structure
2. Egrade the DNA
3. Create positive charge on DNA
4. Cut the DNA sample at various sites.

4. In India, DNA fingerprinting technique was developed by?

1. Dr. Lalji Singh
2. Alec Jeffreys
3. Dr. Khorana
4. None of these.

5. Which of the following is true about DNA fingerprinting?

1. VNTR is used as probe.
2. DNA samples are loaded on agarose gel electrophoresis.
3. It is based on identification of nucleotide sequence present on the DNA molecule.
4. All of these

Distinguish between: Asexual reproduction and Sexual reproduction.

Distinguish between : Systolic blood circulation and Diastolic blood circulation.

Read the following and answer any four questions from (i) to (v) given below:
Study the two cases carefully regarding the pattern of inheritance of disease.

Case	Mother	Father	Children
Case I	With disease	Normal	Sons always with diseases
Case II	With disease	Normal	Sons and daughters could show disease

1. Which of the following diseases is not an example of case I?

1. Haemophilia.
2. Colour blindness.
3. Aa, AA, Aa, Aa, aa
4. Night blindness.

2. Which of the following is impossible for a case I?

1. Carrier mother to pass the gene to her son.
2. Diseased father to pass the gene to his daughter.
3. Diseased father to pass the gene to his son.
4. Carrier mother to pass the gene to her daughter.

3. If inheritance pattern of disease is as case II and both parents are carrier of disease what are the chances of pregnancy resulting in an affected child?

1. 25%
2. 100%
3. 0%
4. 50%

4. Disease that follows inheritance pattern as case I is linked with?

1. Autosomes.
2. X chromosome.
3. Y chromosome
4. Chromosome 21.

5. Study the given pedigree chart showing the inheritance pattern as case II.

Study the given pedigree chart showing the inheritance pattern as case II.

1. Aa, aa, aa, AA, aa
2. Aa, aa, Aa, AA, Aa
3. Aa, Aa, aa, AA, AA
4. Aa, AA, Aa, Aa, aa

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

Distinguish between : Unconditional reflexes and Conditional reflexes