Plant Growth and Mineral Nutrition — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
A desert lizard (an ectotherm) and a mouse (an endotherm) are placed inside a chamber at 15ºC and their body temperature [T(L) for the lizard and T(M) for the mouse] and metabolic rates [M(L) for lizard and M(M) for the mouse] are monitored.

1. Which of the following is correct regardingT(L), M(L), T(M) and M(M)?

1. T(L) and M(L) will fall while T(M) and M(M) will increase.
2. T(L) and M(L) will increase while T(M) and M(M) will fall.
3. T(L) and M(L) will fall, T(M) will remain same and M(M) will increase.
4. T(L) and M(L) will remain same, T(M) and M(M) will decrease.

2. It can be said that some animals in their evolutionary development preferred to be ectotherms than endotherms. Which of the following can be the best suited reason for it?

1. The metabolic reactions of these organisms can occur at a very wide range of temperature.
2. Maintaining homeostasis is an energetically expensive process.
3. The enzymes of these organisms are functional at high temperatures.
4. Both (b) and (c).

3. Organisms that can maintain a constant internal temperature are called.

1. Homoeothermic
2. Poikilothermic
3. Oligothennic
4. Heterothennic

4. An animal that survives at temperature of 10ºC and 40ºC both can be placed under the category of:

1. Ectotherm.
2. Endotherm.
3. Modifiers.
4. Migratory organisms.

5. Study the graph carefully and select the correct option.

1. X could be desert lizard.
2. Y could be mouse.
3. Z could be desert lizard.
4. Both (a) and (b).

Ectomycorrhizae and Endomycorrhizae.

Read the following and answer any four questions from (i) to (v) given below:
Disposal of untreated sewage into the river or freshwater pond causes huge water pollution. Four water samples from different sources (A, B, C, D) are collected and tested for BOD value in a lab to assess their quality. The BOD values are presented in the given table. Water samples are collected from primary effluent, secondary effluent, untreated sewage and river water. Study the given table and answer the following.

Sample	BOD
A	20mg/ L
B	5mg/ L
C	300mg/ L
D	400mg/ L

1. The source of sample 'C' is:

1. River water.
2. Primary effluent.
3. Secondary effluent.
4. Untreated sewage water.

2. If sewage in untreated condition is disposed off in a freshwater body then.

1. BOD and dissolved oxygen both will increase.
2. BOD will increase and dissolved oxygen will decreas.
3. BOD will decrease and dissolved oxygen will increase.
4. BOD and dissolved oxygen both will decrease.

3. A large number of pathogenic microbes can be present in water sample of:

1. C
2. A
3. D
4. Both (a) and (c).

4. High value of BOD in sample O is due to:

1. High amount of organic wastes and aerobic microbes.
2. High amount of inorganic wastes and anaerobic microbes.
3. High amount of organic wastes and anaerobic microbes.
4. High amount of inorganic wastes and aerobic microbes.

5. River water is represented by the sample.

1. A
2. B
3. C
4. D

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.

Distinguish between: Zona pellucida and Corona radiata.

Distinguish between: Asexual reproduction and Sexual reproduction.