Human Health and Diseases — BIOLOGY STD 12 Science — Question

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:
Study the given table and answer the questions based on it.

	Hormone	Source	Function
(A)	Oxytocin	W	Ejection of milk
(B)	X	Anterior lobe of pituitary gland	Stimulates secretion of ABP from Sertoli cells
(C)	Y	Placenta	Maintains corpus luteum to secrete progesterone
(D)	Relaxin	Ovary	Z

1. Identify the hormones X and Y, respectively.

1. Testosterone, FSH.
2. LH, hPL.
3. FSH, hCG.
4. ICSH, hCG.

2. W in the given table is:

1. Hypothalamus.
2. Posterior lobe of pituitary.
3. Placenta.
4. Ovary.

3. Which of the following is correct for Z?

1. Dilation of uterine cervix during labour pains.
2. Stimulates the growth of the mammary glands during pregnancy.
3. Supports the fetal growth and prevents desiccation.
4. Forms protective plug in cervix of uterus during pregnancy.

4. Which set of hormones is secreted only during pregnancy?

1. Human chorionic gonadotropin, relax in and human placental lactogen.
2. Human placental lactogen, estrogen and chorionic thyrotropin.
3. Human chorionic gonadotropin, human placental lactogen and progesterone.
4. Chorionic thyrotropin, chorionic gonadotropin and estrogen.

5. Assertion: Follicle stimulating hormone controls the maintenance and functions of male reproductive organs.

Reason: FSH acts directly on spermatogonia to stimulate sperm production.

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:
While studying inheritance of characters, a teacher gave the example of inheritance of attached earlobe and hypertrichosis of the ear to her students. A man with attached earlobes and extensive hair on pinna married a woman having free earlobes. The couple had four children, one son with attached earlobes and hairy pinna, one son with a free earlobes and hairy pinna and two daughters with attached earlobes. One of the daughters married a man with free earlobes and sparse hair on pinna. Teacher said if this couple would have sons there would be equal chances for both having free or attached earlobes and sparse hair on pinnae.

1. Attached and free earlobe are respective example of?

1. Dominant and recessive traits.
2. Recessive and recessive traits.
3. Recessive and dominant traits.
4. Dominant and dominant traits.

2. Hypertrichosis of the ear is.

1. X linked trait
2. Y linked trait
3. Autosomal dominant trait
4. Autosomal recessive trait.

3. If a female with attached earlobe married a male homozygous for free earlobe sparse hair on pinna then what would be the chances of daughter to have attached earlobe?

1. 0%
2. 100%
3. 25%
4. 75%

4. If a man with attached earlobe and hairy pinna married a woman with attached earlobe then what would be the chances of son to have hairy pinna?

1. 50%
2. 100%
3. 75%
4. 0%

5. A male with attached earlobe, sparse hair on pinna married a female with attached earlobe. Which of the following is correct regarding their progenies?

1. All sons have a free earlobe with hairy pinna.
2. All daughters have an attached earlobe.
3. 50% daughters have an attached earlobe whereas 50% daughters have a free earlobe.
4. 50% sons have attached earlobe with hairy pinna and 50% sons have a free earlobe

Distinguish between: Long day plants and Short day plants

Read the following and answer any four questions from (i) to (v) given below:
Many adaptations are found in flowers to achieve certain kind of pollination. The pollination achieved by insects is known as entomophily. The given diagram shows the cross-section of an anther of an insect pollinated flower.

1. Which of the following is/ are the function(s) of structure Y?

1. To carry waste products away from the anther.
2. To supply oxygen to the cells of the anther.
3. To transport food and mineral salts to the anther.
4. To supply water to the anther.

1. Conly.
2. C and D only.
3. A, B and D only.
4. A, B, C and D.

2. Which of the following most accurately describes the structures found in compartment X?

1. They contain two haploid nuclei resulting from meiosis.
2. They contain two haploid nuclei resulting from mitosis.
3. They contain two haploid male gametes, resulting from mitosis.
4. They contain a vegetative nucleus and pollen tube nucleus.

3. Which of the following is a distinctive characteristic of insect-pollinated flower?

1. All of them have nectar guides on their flowers.
2. They produce sugary fruit.
3. Their pollen grains tend to have rough surfaces.
4. They produce abundant quantities of pollen to make up for pollen grains that might be removed by the wind.

4. Which of the following are likely characteristics of the structures found in X and stamens of this plant?

S. No	Structure of X	Stamens
(a)	Abundant and light	Pendulous
(b)	Rough surfaces	Non-pendulous
(c)	Light and sticky	Pendulous
(d)	Coarse and sticky	Protrude outside the flower

5. Spiny or sticky pollen grains and large, attractively coloured flowers are associated with:

1. Hydrophily.
2. Entomophily.
3. Ornithophily.
4. Anemophily.

Distinguish between: DNA in prokaryotic and eukaryotic cells.