Plant Water Relation — BIOLOGY STD 12 Science — Question

Read the following and answer any four questions from (i) to (v) given below:
In testis, the immature male germ cells produce sperms by spermatogenesis that begins at puberty. It occurs in the seminiferous tubules of the testes. Seminiferous tubules are lined by germinal epithelium. Study the schematic representation of spermatogenesis and answer the following questions.

1. Which cell division occurs during multiplication phase?

1. Mitosis.
2. Meiosis I.
3. Meiosis II.
4. Both (b) and (c).

2. How many chromosomes are present in secondary spermatocyte and spermatid, respectively?

1. 46, 23
2. 46, 46
3. 23, 23
4. 23, XY

3. Transformation of L into M is known as:

1. Spermiation.
2. Spermateliosis.
3. Spermatogenesis.
4. None of these.

4. Select the correct option.

1. Type A spermatogonia grows to larger primary spermatocyte.
2. One spermatogonium forms two spermatids.
3. Spenniation is the release of sperms from seminiferous tubules.
4. Primary spermatocyte undergoes mitosis to form secondary spermatocytes.

5. Which hormone acts on spermatogonia to stimulate sperm production?

1. LH.
2. GnRH.
3. ABP.
4. FSH.

Distinguish between: Passive absorption of Minerals and Active absorption of minerals

Read the following and answer any four questions from (i) to (v) given below:
Rajesh, Ravi, and Rohit are roommates. 'They are doing their graduation. Few months back Ravi fell ill. it took him around 3 weeks to recover. Both his friends were absolutely healthy at that time. After sometime, Rajesh also fell ill from some other disease. This time Ravi and Rohit both contracted the same illness. Based on the above information, answer the following questions.

1. Which of the following holds true for Ravi's illness?

1. Ravi was suffering from a communicable disease that is transmitted through vector.
2. Ravi was suffering from a communicable disease that is transmitted through faecal oral route.
3. Ravi was suffering from a non-communicable disease like anaemia.
4. Ravi was suffering from a non-communicable disease like Down's syndrome.

2. Select the correct statement.

1. Ravi contracted a disease caused by air borne microbes.
2. Ravi could have suffered a nutritional disorder.
3. Ravi suffered a non-contagious disease.
4. Both (b) and (c)

3. Which could be correctly said for Rajesh's illness?

1. Rajesh's illness was due to a microbial infection.
2. Rajesh's illness could be contagious or non-contagious.
3. Rajesh's illness could be cured by antibiotics.
4. All of these

4. Which of the following may depicts Ravi's and Rajesh's illness?

S.no	Ravi	Rajesh
(a)	Which of the following may depicts Ravi's and Rajesh's illness?	Myocardial infection
(b)	Whooping cough	Tetanus
(c)	Gastritis	Rhinitis
(d)	Hypertensio	Thyroid

5. Assertion: Diabetes mellitus is a non-communicable disease which can be completely cured.

Reason: Diabetes mellitus is caused by deficiency of aldosterone hormone.

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:
In angiosperms, the pollen grains are being transferred from the anther to the stigma and is termed pollination. This phenomenon was first discovered by Camerarius (1694) in the end of seventeenth century. Pollen grains are immobile. They cannot reach the stigma by themselves. An external agent is required for this. The pollination is mainly of two types-self pollination and cross pollination. The diagram given below shows two plants of the same species showing different types of pollination.

1. What is transferred between the plants in the process indicated by arrow P?

1. Ova.
2. Pollen.
3. Nutrients.
4. Seeds.

2. Which of the following statements is correct regarding processes P, Q and R?

1. Processes P, Q and R introduce genetic variability in the offspring of sexually reproducing plants X and Y.
2. Wind serves as agent for process Q if plants X and Y belong to Genus Salvia.
3. Flowers of plants X and Y need to produce odour and nectar for completion of processes P and Q if they are entomophilous.
4. If plants X and Y belong to Genus Cannabis, then their flowers need to produce sticky and heavy pollens in very small amount for accomplishment of process Q.

3. Identify the processes P, Q and R.

S. No	P	Q	R
(a)	Geitonogamy	Xenogamy	Autogamy
(b)	Allogamy	Chasmogamy	Cleistogamy
(c)	Autogamy	Geitonogamy	Xenogamy
(d)	Geitonogamy	Allogamy	Autogamy

4. In Catliarantl1us, the growth of style brings the stigma in contact of ripe anthers present on the mouth of corolla tube. This is an example of:

1. Homogamy.
2. Cleistogamy.
3. Geitonogamy.
4. Xenogamy.

5. Which of the given processes represents a type of pollination that would result in greater adaptability of the particular species to potential environmental changes?

1. P.
2. Q.
3. R.
4. All of these.

Read the following and answer any four questions from (i) to (v) given below:
The given graphs show fluctuations in blood sugar of person X and Y during a 24 hour time period.

Based on the above information, answer the following questions.

1. Which of the following holds true for person X?

1. Person X is suffering from type I diabetes.
2. Person X shows severe insulin deficiency and beta cell depletion.
3. Person X is normal and shows good control of blood sugar level.
4. Person X is subjected to excessive urination and abnormal thrust.

2. The given graph indicates that person Y is suffering from.

1. Diabetes
2. Hypertension
3. Atherosclerosis
4. Rheumatic heart disease.

3. Which of the following conditions are common in person Y?

1. Excretion of glucose in urine and excessive urination.
2. Polydipsia and mild beta cell depletion.
3. Progressive erosion of articular cartilage at synovial joint.
4. Both (a) and (b).

4. A person suffering from diabetes mellitus becomes weak because.

1. The cells are unable to utilise glucose and other carbohydrates for energy production.
2. Degradation of fat increases production of toxic ketone bodies.
3. Cells utilise proteins for obtaining energy
4. All of these.

5. Assertion: Type I diabetes involves failure of insulin to facilitate the movement of glucose into cells.

Reason: Type II diabetes is caused by failure of beta cells to produce adequate amount of insulin due to beta cell depletion.

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: Menarche and Menopause.

1. What are the three options that can be thought of, to increase food production?
2. Mention the reasons for the success of Green Revolution in increasing food production.
3. Why do we still search for other alternatives to increase food production?