Human Health and Disease — BIOLOGY STD 12 Science — Question

1. Select the option that correctly identifies autoimmune diseases of Reema, Jai and Ankit.

2. Reema's autoimmune condition is characterised by

1. Undersecretion of insulin.
2. Destruction of RB Cs and low RB C count.
3. Undersecretion of adrenal cortex hormones.
4. Low production of intrinsic factor required for absorption of B₁₂

3. What do you think is the major cause of Jai's condition?

1. Deterioration of myelin sheath around nerve cells, leading to loss of precise muscle control
2. Destruction of heart cells, leading to weakening of entire heart wall.
3. Destruction of beta cells, leading to undersecretion of insulin.
4. Deposition of immune complexes of IgM, IgG and complement in joints thereby inflaming joints, destroying articular cartilage and fusing bones.

4. How do you think Ankit's condition got diagnosed?

1. Low level of thyroid hormone and elevated levels of TSH in Ankit's blood.
2. Presence of antibodies against thyroid pen oxidase (TPO antibodies) in Ankit's blood.
3. Elevated erythrocyte sedimentation rate (ESR), reduced C-reactive protein (CRP) in Ankit.
4. Both (a) and (b)

5. Assertion: Immunosuppressive drugs often reduce the severity of autoimmune disorders.

Reason: Monoclonal antibodies have been successfully used in the treatment of autoimmune disease.

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.

1. Identify the technique adopted by the couple.

1. ZIFT
2. JUI
3. GIFT
4. ICSI

2. What is the pre-requisite of this technique?

1. Gamete formation should be normal.
2. Fallopian tubes should be normal.
3. Female should have thick endometrial lining.
4. Male should be able to copulate the female.

3. Assertion: GIFT is an in-vitro fertilisation technique.

Reason: In GIFT, gametes are fertilised outside the female body.

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. The procedure advised to couple involves the transfer of:

1. Fertilised ovum.
2. Embryo with 8 blastomeres.
3. Sperms and unfertilised ovum.
4. Embryo with 16 blastomeres.

5. What is the success rate of this procedure?

1. 30-50%
2. < 20%
3. 80-85%
4. 27-30%

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.

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.

1. Haploid endosperm is found in:

1. Pin us.
2. Cauliflower.
3. Sunflower.
4. Pea.

2. Persistent endosperm is found in:

P. Pea Q. Castor R. Bean S. Coconut T. Groundnut.

1. Q and S.
2. P and T.
3. R, S and T.
4. P, S and T.

3. Milk of tender coconut represents (A) and the surrounding white coconut meal represents (B).

4. If an endosperm cell of a gymnosperm contains 12 chromosomes, the number of chromosomes in each cell of the root will be:

1. 4
2. 24
3. 16
4. 6

5. In angiosperms, normally after fertilization:

1. The zygote divides earlier than the primary endosperm nucleus.
2. The primary endosperm nucleus divides earlier than the zygote.
3. Both the zygote and primary endosperm nucleus divide simultaneously.
4. Both the zygote and primary endosperm nucleus undergo a resting period.

1. Dodo, an extinct taxon, belongs to which country?

1. Mauritius
2. Africa
3. Australia
4. Russia

2. To which of the following categories of IUCN, Berberis nilghiriensis belongs?

1. Extinct.
2. Extinct in wild.
3. Endangered.
4. Critically endangered.

3. Steller's sea cow and passenger pigeon became extinct due to:

1. Alien species invasion.
2. Over-exploitation.
3. Coextinctions.
4. Intensive agriculture.

4. Bali, Javan and Caspian are:

1. Species of tiger.
2. Species of cheetah.
3. Subspecies of cheetah.
4. Subspecies of tiger.

5. Select the correct term for the following definitions (i, ii, iii, iv).

• The taxon is liable to become extinct if not allowed to realise its full biotic potential by providing protection from exotic species/ human exploitation/habitat deterioration/depletion of food.
• The taxon has been completely eliminated or died out from earth, e.g., Dodo.
• The taxon is facing a high risk of extinction in the wild in the near future due to decrease in its habitat, excessive predation or poaching.
• They are species with naturally small populations, either localised or thinly scattered, which are always at risk from pests/ pathogens/ predators/ exotic species.

1. Which ion is essential for association of both units of ribosome at the time of protein formation?

1. Mg²⁺
2. Mn²⁺
3. CI^-
4. Ca²⁺

2. During translation, how many initiation factors are required in eukaryotes for initiation reactions?

1. 3
2. 6
3. 7
4. 9

3. Which part of mRNA contains untranslated regions (UTR)?

1. 3' end
2. 5' end
3. Either 3' or 5' end
4. Both 5' end and 3' end

4. Name the enzyme that helps in combining amino acid to its particular tRNA?

1. Activating enzyme
2. Amino-acyl tRNA-synthetas
3. PeptidyI transferase
4. Both (a) and (b)

5. From the given list, select the translation machinery.

1. mRNA
2. Ribosomes
3. Amino acids
4. tRNAs
5. Peptidyl transferase
6. Amino acyl tRNA synthetase
7. Pyrophosphatase

1. (1), (2), (3), (4) and (6)
2. (1), (2), (3), (4) and (5)
3. (1), (2), (3), (4), (5) and (6)
4. (1), (2), (3), (4), (5), (6) and (7)