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Part 127 – Biology Previous Year Questions

Q1. In bio fortification technique plant breeders use breeding to overcome
(a) Loss due to insect pests
(b) Decrease in food production
(c) Deficiencies of micronutrients and vitamins
(d) Loss due to plant diseases
Ans: (c) Biofortification refers to the breeding of crops to increase their nutritional value. The crops produced through biofortification method are always rich in nutrients like iron, zinc and Vitamin A. for example, Golden rice was produced using the method of biofortification. This rice is rich in beta-carotene and provides vitamin A to the children.

Q2. DOTS is a treatment given to patients suffering from

(a) Polio (b) AIDS
(c) Hepatitis (d) Tuberculosis
Ans: (d) DOTS (Directly Observed Treatment, Short Course), also known as TB-DOTS, is the name given to the tuberculosis control strategy recommended by the World Health Organization. It is the best curative method for treatment of tuberculosis because of its highly efficient and cost-effective strategy.

Q3. Magnesium is a constituent metal of

(a) Chlorophyll molecule
(b) DNA
(c) Mitochondria
(d) Ribosomes
Ans: (a) The basic structure of chlorophyll consists of a porphyrin ring, coordinated to a central atom. This is very similar in structure to the heme group found in hemoglobin, except that in heme the central atom is iron, whereas in chlorophyll it is magnesium. This was discovered in 1906 and was the first time that magnesium had been detected in living tissue.

Q4. Name the gas used in preparation of bleaching powder

(a) Oxygen (b) Hydrogen
(c) Nitrogen (d) Chlorine
Ans: (d) Bleaching powder (CaOCl2) in manufactured by passing chlorine gas over dry slaked lime. Bleaching powder is also called calcium chlorohypochlorite because it is considered as a mixed salt of hydrochloric acid and hypochlorous acid.

Q5. Rio Summit is associated with

(a) Convention on Biological Diversity
(b) Green house gases
(c) Ozone depletion
(d) Wet lands
Ans: (a) The United Nations Conference on Environment and Development (UNCED), otherwise known as the Earth Summit or Rio Summit, was held in Rio de Janeiro, Brazil, in June 1992. An important achievement of the summit was an agreement on the Climate Change Convention. Besides, the Convention on Biological Diversity was opened for signature at the Rio Summiton 5 June 1992 and entered into force on 29 December 1993.

Q6. Polyploidy arises due to change in the

(a) number of chromatids
(b) structure of genes
(c) number of chromosomes
(d) structure of chromosomes
Ans: (c) An organism having more than two sets of homologous chromosomes is known as polyploid and the phenomenon polyploidy.Polyploidy refers to a numerical change in a whole set of chromosomes. Polyploidy may occur due to abnormal cell division, either during mitosis, or commonly during metaphase I in meiosis.

Q7. The largest artery in human body is

(a) Aorta
(b) Capillary
(c) Vena cava
(d) Pulmonary vein
Ans: (a) The aorta is the largest artery of the human body. It is an artery that directly arises from the heart itself and descends through the thorax and into the abdomen. All the arteries of the body, save the pulmonary arteries, stem from the aorta or one of its main branches.

Q8. Smooth muscles are likely to be found in

(a) muscles of legs
(b) muscles of arms
(c) stomach
(d) heart
Ans: (c) The term smooth muscle refers to a muscle of the human body that is part of a involuntary muscle group. The walls of hollow organs are the primary place that smooth muscles can be found. Some of those locations include: Walls of blood vessels, walls of stomach, intestines, large (aorta) and small arteries, arterioles and veins, urinary bladder, uterus, male and female reproductive tracts, respiratory tract,etc.

Q9. The substrate of photorespiration is

(a) Fructose (b) Pyruvic acid
(c) Glycolate (d) Glucose
Ans: (c) Photorespiration is a special type of respiration shown by many green plants when they are exposed to light. Glycolate (glycolic acid) is the chief metabolite of photorespiration and also its substrate. Other important metabolites are the amino acids glycine and serine.

Q10. The waste management technique that involves the use of micro-organisms to remove or neutralize pollutants from contaminated site is called

(a) Bio sensor
(b) Bio magnification
(c) Bio remediation
(d) Bio concentration
Ans: (c) Bioremediation is a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site. It uses naturally occurring organisms to break down hazardous substances into less toxic or non-toxic substances. There are two classes of bioremediation used : In situ and Ex situ.

Q11. Who is known as the ‘Father of Green Revolution’ in India?

(a) G. Paul
(b) Norman Borlaug
(c) Van Neil
(d) Dr. Mithchell
Ans: (b) Norman Borlaug, an American biologist and humanitarian, is globally known as the Father of Green Revolution forintroducing techniques that contributed to the extensive increases in agricultural production. He is credited with saving over a billion people worldwide from starvation. M. S. Swaminathan is known as “Indian Father of Green Revolution” for his leadership in introducing and further developing highyielding varieties of wheat in India.

Q12. The oxygen liberated during photosynthesis comes from

(a) Water
(b) Carbon dioxide
(c) Glucose
(d) Chlorophyll
Ans: (a) The oxygen produced during photosynthesis comes from water. The electrons excited by light in the chlorophyll molecule are replaced by electrons produced from the oxidation of water into oxygen. Photosynthesis combines water and carbon dioxide into sugars, leaving oxygen gas as a waste product.

Q13. Kyoto Protocol is associated with

(a) Species conservation
(b) Climate change
(c) Wetland Conservation
(d) Medicinal plants
Ans: (b) The Kyoto Protocol is an international agreement linked to the United Nations Framework Convention on Climate Change, which commits its Parties by setting internationally binding emission reduction targets. It was adopted in Kyoto, Japan, on 11 December 1997 and entered into force on 16 February 2005.

Q14. Meibomian glands are located in

(a) Eye (b) Ear
(c) Nose (d) Skin
Ans: (a) Meibomian glands are the tiny oil glands which line the margin of the eyelids (the edges which touch when the eyelids are closed). These glands secrete oil which coats the surface of our eyes and keeps the water component of our tears from evaporating (drying out). Together, the water and the oil layer make up the tear film.

Q15. Which of the following vitamins are water soluble?

(a) Vit. A and Vit. B
(b) Vit. B and Vit. C
(c) Vit. C and Vit. D
(d) Vit. A and Vit.
Ans: (b) Vitamins are classified as either fat soluble (vitamins A, D, in English and K) or water soluble (vitamins B and C).The fat soluble vitamins are soluble in lipids (fats); water-soluble vitamins are those that dissolve in water upon entering the body. Because of this, our body cannot store excess amounts of water-soluble vitamins for later use.

Q16. Green House Effect’ means

(a) Pollution in houses in tropical region
(b) Prevention of ultraviolet radiation by the ozone layer
(c) Trapping of solar energy due to atmospheric gases
(d) Damage to green painted buildings
Ans: (c) The greenhouse effect occurs when Earth’s atmosphere traps solar radiation because of the presence of certain gases, causing the heating of the earth. These greenhouse gases include water vapor, CO2, methane, nitrous oxide (N2O) and other gases, according to the Environmental Protection Agency (EPA).

Q17. Honey that has high concentration of sugar does not decay because

(a) Bacteria cannot survive in an active state as it is totally deprived of oxygen
(b) It contains natural antioxidant that prevents bacterial attack
(c) Bacteria cannot survive in an active state in a solution of high osmotic strength as water is drawn out
(d) None of these
Ans: (c) The reason why bacteria doesnot grow in high concentration of sugar is because of sugar’s high osmotic and dehydrating effects. Sugar, whether in solid or aqueous form, attempts to reach equilibrium with the sugar content of the food product with which it is in contact. This has the effect of drawing available water from within the food to the outside and inserting sugar molecules into the food interior. The result is a reduction of the so-called product water activity (aw), a measure of unbound, free water molecules in the food that is necessary for microbial survival and growth.Sugar’s other antimicrobial mechanisms include interference with a microbe’s enzyme activity and weakening the molecular structure of its DNA (Scientific American Journal).

Q18. Which of the following mammals lay eggs?

(a) Bat (b) Whale
(c) Weasel (d) Platypus
Ans: (d) The platypus, also known as the duck-billed platypus, is a semiaquatic egg-laying mammal endemic to eastern Australia, including Tasmania. Together with the four species of echidna, it is one of the five extant species of monotremes, the only mammals that lay eggs instead of giving birth.

Q19. What does the term ‘Ebola’ stand for?

(a) A viral disease outbreak in West Africa
(b) A viral disease outbreak in Bangladesh
(c) A city in Syria destroyed by ISIS.
(d) None of these
Ans: (a) Ebolais a viral hemorrhagic fever of humans and other primates caused by ebolaviruses. The largest outbreak to date of Ebola was the epidemic in West Africa, which occurred from December 2013 to January 2016 with 28,616 cases and 11,310 deaths.

Q20. The virus of AIDS affects the growth of _________

(a) Haemoglobin
(b) RBCs in blood
(c) T cells in blood
(d) Grey cells in brain
Ans: (c) Human immunodeficiency virus (HIV) attacks and kills crucial immune system cells, known as T-helper cells. A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity. They are called T cells because they mature in the thymus from thymocytes.

Q21. Gustation refers to the sense of which of the following ?

(a) Smell (b) Hearing
(c) Tactile (d) Taste
Ans: (d) Gustation is usually called the sense of taste. Taste is the sensation produced when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue.Taste cells are gathered together in taste buds on the tongue, and taste buds are hidden in bumps on the tongue called papillae.

Q22. What is commonly known as ‘white plague’?

(a) Typhoid (b) Malaria
(c) Tuberculosis (d) Plague
Ans: (c) Tuberculosis was known as the white death and the great white plague during the 19th century. Tuberculosis is an infectious disease caused by the bacterium Mycobacterium tuberculosis (MTB). It can occur in any organ of the body but is most well known in the lung.

Q23. Which of the digestive organs contains acid?

(a) Stomach
(b) Small intestine
(c) Appendix
(d) Colon
Ans: (b) Gastric acid, gastric juice or stomach acid, is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl), potassium chloride (KCl) and sodium chloride (NaCl). Gastric acid plays a key role in digestion of proteins, by activating digestive enzymes.

Q24. Which of the following fibres is considered as the strongest natural fibre?

(a) Cotton (b) Jute
(c) Wool (d) Silk
Ans: (d) Ultrastrong spider silk is one of the toughest natural fibers known in nature. The light, flexible fiber is five times stronger by weight than high-grade steel and extremely stretchy, enlarging to snag incoming insects and other prey.

Q25. Potato is a

(a) Root (b) Stem
(c) Bud (d) Fruit
Ans: (b) Potatoes are examples of tubers : the swollen ends of stolons that may store starch. It is a stem because it has many nodes called eyes with spaces between eyes known as internodes. Potato tubers develop at the end of swollen underground stem structures, rhizomes. Eyes of potatoes are really axillary buds which contain several small buds at each site. These buds can expand to form shoots which grow on to make whole plants.

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