NIOS Class 12 Biology Apr 2022 Set B (63/OSS/1)

NIOS Biology Question Paper April 2022 Set B

1 MARK QUESTIONS

1. Which of the following is a broad-spectrum antibiotic? 

(A) Penicillin 

(B) Erythromycin 

(C) Paracetamol 

(D) Streptomycin 

2. Which of the following antibodies is present in Colostrum that provides immunity to the newborn infant? 

(A) IgG 

(B) IgE 

(C) IgM 

(D) IgA 

3. What does the following sequence represent? 

(A) Genetic Drift 

(B) A food Pyramid 

(C) Ecological Succession 

(D) Phylogenetic trend 

4. One of your class fellow put some dry grams in water overnight. Next morning, it was fully swollen. Name the phenomenon involved. 

(A) Osmosis 

(B) Imbibition 

(C) Plasmolysis 

(D) Diffusion 

5. Identify the locomotory organs of starfish. 

(A) Parapodia 

(B) Radiating Arms 

(C) Setae 

(D) Tubefeet 

6. Which of these plants exhibits a parasitic mode of nutrition? 

(A) Cuscuta 

(C) Monotropa 

(B) Money plant 

(D) Nepenthes 

7. The cell wall is made up of a chemical which is unique in bacteria. Name the chemical. 

(A) Peptidoglycan 

(B) Chitin 

(D) Cellulose  

(C) Lignin 

8. A baby is born with a genetic disorder. His cells have 47 chromosomes, and his karyotype is 45 + XY. Name the disorder he is suffering from: 

(A) Sickle cell anaemia 

(C) Down’s Syndrome 

(B) Turner’s Syndrome 

(D) Klinefelter’s Syndrome 

2 MARK QUESTIONS

9. Distinguish between Antigen and Antibody. 

Ans: An antigen is any foreign molecule that can trigger a specific immune response. An antibody is a protein molecule produced in animals in response to an antigen.

10 Distinguish between Mutualism and Symbiosis. Write one suitable example of each from animal world. 

Ans: Mutualism is a close association between two species in which both species benefit. Symbiosis is a type of mutualism where the interacting species cannot live without each other, as they depend completely on each other for their survival. 

11. Draw a neat diagram of a longitudinal section of a typical flower and label the four whorls. 

Ans: 

12. Name the surgical methods of Contraception in human males and females. Also mention the basic procedure involved in the two methods. 

Ans: 

• Vasectomy in males, where the vas deferens is ligated (tied) by the surgeon to prevent sperm from going out of the body.
• Tubectomy in females, where the fallopian tubes are cut and ligated to prevent the ovulated egg from passing down for fertilisation.

13. Expand the following abbreviations and state how they are useful in daily life. 

(a) CNG 

(b) PNG 

Ans: 

1. CNG: Compressed Natural Gas
2. PNG: Piped Natural Gas

14. After a surgery, a man was advised to include more proteins and Iron in his diet. Give reasons and also mention one source of each nutrient. 

Ans: 

• Protein – body-building food required during healing after surgery.
  • Source: Dal, pea, beans, soybean, gram (any one)
• Iron: Builds blood as it is part of the Hb molecule.
  • Source: Liver, Leafy vegetables like spinach, egg, molasses, grains, peanuts (any one)

15. Where can you locate the following structures in plants? 

(a) Perianth 

(b) Bulliform cells 

Ans: 

1. On the flower whorls
2. Inside the epidermis of monocot leaves

16. (a) Expand the abbreviation PEM. 

(b) Write the Name of one disease caused due to PEM. 

Ans: 

1. Protein Energy Malnutrition (PEM)
2. Marasmus

17. Name the Phytohormones involved in the following functions: 

(a) Promotes cell elongation 

(b) Induces ripening of fruits 

Ans: 

1. Auxin
2. Ethylene

18. Draw a neat and labelled diagram of an Open Stomata in a Monocot plant. 

Ans: 

19. (a) Write the name of the hormone secreted by the Human Placenta. 

(b) Write the name of the hormone which stimulates the development of male characteristics during puberty. 

Ans: 

1. The placenta produces the hormone progesterone.
2. Testosterone

20. Why do insectivorous plants eat insects, when it is capable of carrying out photosynthesis? 

Ans: Insectivorous plants eat insects when it is capable of carrying out photosynthesis to overcome nitrogen deficiency, as they grow in soils having acute nitrogen deficiency. 

4 MARK QUESTIONS

21. (a) What are Vaccines? What do you understand by second-generation vaccines? Write the names of any two diseases for which these vaccines are already in use. 

(b) Expand BCG and mention its usage. 

Ans: 

1. Vaccines are biological preparations that contain mild or attenuated (weakened) germs that are introduced into the body to induce the immune system to produce necessary antibodies. Second-generation vaccines are vaccines that are produced by genetic engineering or recombinant DNA technology. Eg., Vaccines for Hepatitis B and Herpes.
2. BCG – Bacillo Calmette-Guérin. It is given to prevent tuberculosis.

22. (a) Draw a neat and proportionate diagram of the Female reproductive system of humans. Label its four parts. 

(b) Where do the following processes take place? 

(i) Fertilisation 

(ii) Implantation 

Ans: 

1. Female reproductive system in humans

2. These processes take place
   1. Fertilization: fallopian tubes
   2. Implantation: Wall of the uterus

23. (a) Where are the two biodiversity Hot – SPOTS found in India? 

(b) Distinguish between In Situ Conservation and Ex-situ Conservation. Also write one suitable example of each. 

(c) With the help of a suitable example, define the term Endangered species.

Ans: 

1. The eastern Himalayan hot spot extends to the north–eastern India and Bhutan. The Western Ghats extend from the southwest towards Gujarat.
2. In-situ conservation includes the protection of plants and animals within their natural habitats or in protected areas. Ex-situ conservation is the conservation of plants and animals outside their natural habitats.
3. Endangered species are those which have been reduced in number to a critical level and are facing a high risk of extinction in the near future. E.g.. Asiatic lion.

24. Draw labelled diagrams: 

(a) A series of stages in the budding of yeast. 

(b) Amoeba showing Binary fission 

Ans: 

1. Budding of yeast

2. Binary fission in Amoeba

25. (a) Draw a double helical structure of DNA. 

(b) Write the names of the scientists who proposed this model. 

Ans: 

1. Helical structure of DNA

2. Scientists who discovered the helical structure of DNA are Franklin and Wilkins.

26. (a) With the help of a flow chart, show the non-cyclic Photophosphorylation taking place in Photosynthesis. Mention the products formed in this phase. 

(b) Where does this process take place in plants? 

Ans: 

1. Non-cyclic photophosphorylation

The products formed in this phase are ATP, NADPH₂ and O₂. 

2. It takes place in the thylakoid membranes of the chloroplast.

6 MARK QUESTIONS

27. (a) Draw a neat and labelled diagram of the Excretory organs in humans. 

(b) List the role of liver in Excretion. (2 points) 

(c) Write the name the excretory organ in Cockroach. 

Ans: 

1. Excretory organs in humans

2. The liver breaks down excess amino acids into urea and sugar. Urea is excreted in urine, and sugar is stored for use.
3. Malpighian tubules.

28. (a ) Mention the four characteristics features of class Mammalia. 

(b) State the main difference between Metatheria and Eutheria. Write one suitable example of each. 

(c) Write the scientific names of the following: 

(i) Human being 

(ii) Wall lizard 

Ans: 

1. Main characteristics of Class Mammalia are,
   1. Body covered with hair.
   2. Presence of milk (Mammary) glands.
   3. Sweat and oil glands are present in the skin.
   4. The body is divisible into head, neck, trunk and tail; the tail is absent in some.
2. Scientific names
   1. Human being: Homo sapiens
   2. Wall lizard: Hemidactylus

29. (a) Explain the Sex Determination in Humans. Differentiate between Homogametic and Heterogametic individuals. 

(b) A colour blind man marries a woman who has normal colour vision. A son and a daughter born to them are colour blind. Explain this with the help of a self-explanatory flow chart 

Ans: 

1. Sex chromosomes in human males are morphologically dissimilar – XY. They produce two different gametes- X and Y. They are called heterogametic individuals. Human females carry similar sex chromosomes, XX, and they produce similar gametes, such as X and X. They are called homogametic individuals. When an egg (X) is fertilised by an X gamete from the father, the child becomes a female, and if the egg is fertilised by a Y gamete, the child will be a male.
2. For both the son and daughter to be colour blind, the mother must not be a carrier as the gene for colour blindness comes from the X chromosome. Since the mother has normal vision, she carries a normal gene. Thus, their genotypes could be

Father: XᶜY (affected) and Mother: XᴺXᶜ (carrier)

	Xᴺ (mother)	Xc (mother)
Xᶜ (father)	XᶜXᴺ	XᶜXᶜ
	(daughter — carrier, normal vision)	(daughter — colour blind)
Y (father)	XᴺY	XcY
	(son — normal vision)	(son — colour blind)

30. (a) With the help of a flow chart, describe the steps involved in the Coagulation of blood. 

(b) Why is a person with blood group ‘AB’ called a Universal recipient? 

(c) Give an example of a lymphoid organ? Name the two major types of cells present in them and state the general function they perform in the body. 

Ans: 

1. Steps in the coagulation of blood.

2. Blood group AB can receive blood from all other groups and is thus called a Universal Recipient. No Antibodies present in the blood of Group AB, so no reaction with antigens of other blood groups.
3. The spleen is the largest lymphoid organ that helps destroy old and worn-out blood cells or RBCs. Cells found in the spleen are T-cells and B-cells.

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