Molecular Basis of Inheritance — BIOLOGY STD 12 Science — Question

Distinguish between: m-RNA, t-RNA and r-RNA.

Read the following and answer any four questions from (i) to (v) given below:
Ginkgo tree has been saved from extinction by selective breeding followed by channeling into trade of nature lovers. This is an ex-situ conservation, where endangered species are protected from all adverse factors. Offspring produced in captive breeding are released in natural habitat for acclimatisation.

1. What is the significance of offsite collections?

1. Restock depleted populations.
2. Protection of endangered species.
3. Reintroduce species in wild.
4. All of these.

2. Which of the following is not an ex-situ conservation?

1. Wetlands
2. Orchards
3. Aquaria
4. Botanical gardens.

3. Select the incorrect statements for ex-situ conservation.

1. It is conservation of species outside their natural habitats.
2. Endangered species are kept under human supervision and provided all the essentials.
3. The species population recovers in natural environment.
4. Both (b) and (c).

4. Conditions maintained in seed banks for orthodox seeds are:

1. Low moisture content.
2. Anaerobic conditions.
3. Low temperature.
4. All of these.

5. Assertion: Animal species which have become extinct in wild continue to be maintained in zoological parks.

Reason: Captive breeding is the conservation of those cases where these is no realistic chance of in-situ survival.

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.

Outcrossing and Crossbreeding.

Read the following and answer any four questions from (i) to (v) given below:
Kangaroo rat seldom drinks water. It has thick coat to minimise evaporative desiccation. TI1e animal seldom comes out of its comparatively humid and cool burrow during the day time. 90% of its water requirement is met from metabolic water (water produced by respiratory breakdown of fats) while 10% is obtained from its food. Loss of water is minimised by producing nearly solid urine and faeces. As the animal faces acute water scarcity, it develops two types of adaptations : reducing water loss and ability to tolerate desert conditions.

1. Kangaroo rat is a:

1. Partial regulators
2. Partial conformer
3. Regulator
4. Conformer

2. Metabolic water refers to:

1. Water required for metabolic activities.
2. Water present in intercellular fluid.
3. Water produced during oxidation of fat or carbohydrate.
4. Water taken in, to promote metabolism.

3. Desert animals minimise water loss by:

1. Producing highly concentrated urine.
2. Promoting maximum reabsorption of water in kidney tubules.
3. Possessing one of the longest loop of Henle in kidney tubules.
4. All of these.

4. Assertion: Kangaroo rat can tolerate and thrive in wide temperature range and is known as stenothermal.

Reason: Kangaroo rats go into hibernation during winter to escape cold weather.

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. The adaptations in an organism are meant for:

1. Optimum primary production.
2. Optimum life span.
3. Optimum mobility.
4. Optimum survival and reproduction.

Distinguish between : In-situ and ex-situ conservation.

Distinguish between : Extero and entero receptors.

Distinguish Between: Homozygous and Heterozygous.

Read the following and answer any four questions from 9(i) to 9(v) given below:
Bioreactors are considered as vessels in which raw materials are biologically converted into specific products by microbes, plant and animal cells or their enzymes. They are used for large scale production as they provide optimum growth conditions such as temperature, pH, substrate, vitamins, oxygen and salts for obtaining desired product. Most commonly used bioreactors are of stirring type which include simple stirred tank bioreactor and sparged stirred-tank bioreactor.

1. Bioreactor are useful in:

1. Amplifying a gene.
2. Isolation of genetic material.
3. Processing large volume of culture.
4. Infecting DNA in a cell.

2. Which of the following is essential to obtain desired product in a bioreactor?

1. Size of the bioreactor.
2. Sterile condition.
3. Quantity of the raw material.
4. All of these.

3. Assertion: The stirred-tank is well suited for large scale production of microorganisms under aseptic conditions.

Reason: In sparged stirred tank bioreactor, surface area for oxygen transfer is increased.

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.

4. Growth condition that could affect the quality of obtained product in a bioreactor are:

1. Temperature and pH only.
2. pH and oxygen supply only.
3. Temperature and oxygen supply only.
4. Temperature, pH and oxygen supply.

5. Vessels in which raw materials are biologically converted into specific products are.

1. Bioreactors.
2. Fermentors.
3. Gene guns.
4. Both (a) and (b).