Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

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

Human male reproductive system comprises of a pair of testes, primary sex organs associated with formation of gametes and production of sex hormone. Study the given figure of human male reproductive system and answer the following questions.

1. Which of the following is correct for labelled part P?

1. P is rete testis which transports sperms to outside.
2. P is epididymis which secretes fluid that nourish the sperms.
3. P is epididymis that carry sperms and secretion of seminal vesicles.
4. P is rete testis, which lies along inner side of each testis and stores the sperms.

2. Identify the correctly matched pair.

1. Q - Vasa efferentia.
2. R - Ejaculatory duct.
3. S - Seminal vesicle.
4. T - Cowper's gland.

3. Which statement is incorrect for Q?

1. It carries spermatozoa from epididymis to ejaculatory duct.
2. Q are only 2 in number.
3. It arises from rete testis.
4. It constitutes male sex accessory duct.

4. Which structure passes through the prostate gland and carries sperms and secretion of seminal vesicle?

1. P.
2. T.
3. S.
4. R.

5. Assertion: Mucus present in secretion of bulbourethral gland decreases the number of sperms damaged during ejaculation.

Reason: Mucus lubricates the end of penis and lining of the urethra.

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.

Microbes can be used to decrease the use of chemical fertilizers and pesticides. Explain how this can be accomplished.###How biofertilizers increase fertility of soil?

Give a brief account of evolution of vertebrates.

Read the following and answer any four questions from (i) to (v) given below:
Wetlands are called Ramsar sites because the first international convention on their conservation was held in Ramsar in Iran in 1971. Wetlands or Ramsar sites are low lying marshy areas which get filled up during rains due to runoff and overflow from other water bodies. They are often considered to be waste lands which are used as dumping areas and filled up to recover land for various constructions activities. As a result, a large number of wetlands have disappeared.

1. Select the incorrect match of wetland and its location.

	Wetland	Location
(a)	Harike	Punjab
(b)	Chandra Tai	H.P.
(c)	Bhoj	M.P.
(d)	Ashtamudi	Odisha

2. Migratory bird flamingo breeds in which of the following wetlands?

1. Bhitarkanika Mangroves.
2. Rann of Kutch.
3. Harike.
4. Chandra Tal.

3. Which of the following is not an importance of wetlands?

1. They are an important source of recharging groundwater.
2. They provide protection from floods.
3. They are good source of siltation and purification of water.
4. None of these.

4. Which of the following wetland ecosystem is highly acidic and has a accumulation of decomposed plants known as peat?

1. Bog
2. Mangrove
3. Estuary
4. Watershed

5. The mangroves of Bhitarkanika are famous for:

1. Rare migratory waterbirds.
2. Nesting sites for endangered olive ridley turtles.
3. Prawn cultivation.
4. All of these.

Read the following and answer any four questions from (i) to (v) given below:
The DNA, which is transferred from one organism into another by joining it with the vehicle DNA is called passenger or foreign DNA. Generally three types of passenger DNAs are used. These are complementary DNA (cDNA), synthetic DNA (sDNA) and random DNA. Complementary DNA (cDNA) is synthesized on RNA template (usually mRNA) with the help of reverse transcriptase. Synthetic DNA (sDNA) is synthesized on DNA template or without a template. Random DNA are small fragments fanned by breaking a chromosome of an organism in the presence of restriction endonucleases.

1. Reverse transcriptase enzyme was discovered by:

1. Temin and Baltimore.
2. Cohen and Boyer.
3. Arber and Nathan.
4. Paul Berg.

2. During cDNA formation, what would happen if DNA formed by reverse transcriptase is not treated with the alkali?

1. cDNA will not be digested.
2. mRNA will not be digested.
3. Hydrogen bonds will not form between base pairs.
4. rnRNA will not be formed.

3. Enzyme that helps in the formation of double stranded cDNA is:

1. DNA synthetase
2. Ligase
3. DNA polymerase
4. Helicase.

4. DNA polymerase can be obtained form:

1. Retrovirus.
2. Agrobacteriurn.
3. Tobacco mosaic virus.
4. Thermus aquaticus.

5. DNA synthesised without a template is referred to as:

1. Complementary DNA.
2. Random DNA.
3. Synthetic DNA.
4. Z-DNA..

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

A woman unable to conceive after many years of regular unprotected coitus went to specialised infertility clinic. On complete examination, woman was found to be normal, while male partner was diagnosed with infertility. Male partner is unable to copulate the female. Couple was advised to opt for assisted reproductive technology (ART).

1. Which ART could have been useful for this couple?

1. ZIFT
2. IUT
3. AI
4. GIFT

2. In which of the following infertility issues could this technique be used?

1. Anovulation.
2. Oligospermia.
3. Low fructose content in seminal fluid.
4. All of these.

3. Which among the following techniques is useful to conceive when there is very low sperm count?

1. GIFT
2. Test-tube baby
3. IUT
4. JCSI

4. Assertion: Artificial insemination (AI) is intra-uterine insemination.

Reason: In Al, sperms collected from donor are introduced into the uterus.

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

5. Success rate of artificial insemination technique is:

1. 20-40%
2. 60-70%
3. 40-50%
4. 5-7%

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

Aditya went to his hometown located in countryside along with his parents during his summer vacations. His grand parents' house is surrounded by farmland from all sides. Lots of crops were growing nearby and Aditya was very excited to visit the crop fields. He seeked permission from his mother to play in farmland along with his friends and then went to play in the fields. On returning back he had running nose, watering eyes and continuous sneezing which was very frequent. TI1e symptoms worsened with time. Based on the above information, answer the following questions.

1. What could be the possible reason for Aditya's condition?

1. Allergy
2. Infection
3. Malnutrition
4. Genetic disorder

2. How can allergy be diagnosed in a person?

1. Presence of large amount of IgE antibodies in the blood.
2. Presence of large number of bacteria in the blood.
3. Presence of bilirubin and bilirubin pigments in the stool.
4. Presence of sickle shaped RBCs in the blood

3. The symptoms which Aditya developed on account of being allergic are consequence of?

1. Inflammation of membrane lining the nose and conjunctiva
2. Swelling up of tissue surrounding bronchioles of lungs
3. Dilation of all arteries so that large amount of fluid passes from blood to tissues.
4. All of these.

4. Name the type of allergy that Aditya developed.

1. Asthma
2. Anaphylaxis
3. Hay fever
4. Urticaria

5. Assertion : Hay fever is the form of allergy due to pollens of grasses and other plants.

Reason : Hay fever symptoms are due to release of histamines and often respond well to treatment with antihistamines.

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.

Read the following and answer any four questions from (i) to (v) given below:
The Kakapo is the world's largest and heaviest parrot, found only in New Zealand. It is unusual in that it is nocturnal, flightless and ground-dwelling. It is an excellent climber of trees, has strong legs that allow it to "jog" several kilometres in a single trip, and has mossy green plumage mottled with brown and yellow. The Kakapo is also critically endangered as of now, there were only few known living individuals left.

1. Which could be the possible reason for Kakapo to be well-adapted to its environment prior to the arrival of humans in New Zealand?

1. Kakapo was active only in the night when its potential predators would not be out for hunting.
2. The Kakapo would likely be well-camouflaged among the forest foliage due to its greenish plumage.
3. It was able to effectively hunt for food in the night.
4. All of these.

2. When humans started to settle in New Zealand, they took with them non-native animals, including mammals such as cats, dogs and stoats. By which of the following ways, human settlement likely contributed to a near decimation of Kakapo populations in New Zealand?

1. Habitat destruction.
2. Alien species invasion.
3. Pollution.
4. Both (a) and (b).

3. All known survived Kakapo have been relocated by the New Zealand government to three predator-free islands, where they are monitored year round by staffs and volunteers to ensure that the birds are safe, healthy and well-fed. The extremely low population of Kakapo is a hurdle to the species becoming viable in the long term, despite such dedicated conservation efforts. This is because.

1. The small population results in very small gene pool.
2. There would be very Ii mited genetic diversity among the resulting offspring.
3. Of reduced capacity of the species to adapt and survive changes in the environment.
4. All of these.

4. The reasons behind conserving biodiversity have been grouped into which of the following categories?

1. Narrowly utilitarian.
2. Broadly utilitarian.
3. Ethical.
4. All of these.

5. One of the ex situ conservation methods for endangered species is:

1. Wildlife sanctuaries.
2. Biosphere reserves.
3. Cryopreservation.
4. National parks.

Define ecological pyramids and describe with examples, pyramids of number and biomass.

A regulatory body working under MoEF for the release of transgenic crop is ____________:

1. NBPGR
2. NSC
3. NIPGR
4. GEAC