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Part 128 – Biology Previous Year Questions

Q1. Haematopoiesis take place in
(a) Lungs (b) Pancreas
(c) Liver (d) Bone marrow
Ans: (d) Haematopoiesisis the formation of blood cellular components. The sites where haematopoiesis occurs change during embryonic development, but in adult mammals, the bone marrow is the major site of haematopoiesis. Haematopoietic stem cells in the bone marrow reside in a specialised microenvironment known as the hematopoietic stem cell niche, composed of osteoblasts, mesenchymal cells and sinusoidal vessels.

Q2. ______ is a hormone that regulates the amount of glucose in the blood

(a) Glucogen (b) Thyroxine
(c) Oxytocin (d) Insulin
Ans: (d) Insulin is a hormone that allows our body to use sugar (glucose) from carbohydrates in the food that we eat for energy or to store glucose for future use. Insulin helps keeps our blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia).Insulin is a peptide hormone produced by beta cells of the pancreatic islets.

Q3. Pellagra and Scurvy are caused by which pair of vitamin deficiency respectively

(a) Vitamin C and Vitamin D
(b) Vitamin B-12 and Vitamin C
(c) Vitamin C and Vitamin A
(d) Vitamin A and Vitamin B-12
Ans: (*) Pellagra defines systemic disease as resulting from a marked cellular deficiency of niacin (vitamin B3). It is characterized by 4 “D’s”: diarrhea, dermatitis, dementia, and death. Scurvy is a state of dietary deficiency of vitamin C (ascorbic acid). It causes general weakness, anemia, gum disease, and skin hemorrhages.

Q4. The suicidal bags of the cell are

(a) Lysosomes
(b) Ribosomes
(c) Dictyosomes
(d) Phagosomes
Ans: (a) Lysosomes are called the suicide bags of the cells they contain digestive enzymes, and break down food, cellular debris and foreign invaders like bacteria. When the cell is injured beyond repair, or becomes old, the lysosome digests the cell. So, it is called “suicide bag of the cell.”

Q5. Who among the following is credited with starting the work on plant tissue culture?

(a) F.C. Steward
(b) P. Maheshwari
(c) P.R. White (d) Haberlandt
Ans: (d) G. Haberlandt, a German botanist, in 1902 cultured fully differentiated plant cells isolated from different plants. This was the very first step for the beginning of plant cell and tissue culture. Further contributions were made by the Cell Doctrine which admitted that a cell is capable of showing totipotency.

Q6. What causes the mottling of the dental enamel?

(a) High levels of chlorine in water
(b) High levels of nitrate in the water
(c) High levels of fluorides in the water
(d) High levels of calcium in the water
Ans: (c) The mottling of dental enamel is an extremely common disorder, characterized by hypomineralization of tooth enamel caused by ingestion of excessive fluoride during enamel formation. It is also known as dental fluorosis. Common causes of fluorosis include: fluoridated drinking water (particularly during infancy), ingestion of fluoride toothpaste, use of fluoride tablets, and consumption of processed foods made with fluoridated water.

Q7. Blood is red in colour due to the presence of __________ .

(a) Cytochrome
(b) Chlorophyll
(c) Hemocyanin
(d) Haemoglobin
Ans: (d) The red color of blood comes from the hemoglobin that makes up the majority of the mass of the cell, which allows the blood cell to carry oxygen around the body. The plasma itself is a straw color when viewed under a microscope, but the hemoglobin makes up so much of the blood cell that its red color overpowers the color of the plasma.

Q8. Which one of the following events in a botanical garden is never directly influenced by light ?

(a) Flowering
(b) Photosynthesis
(c) Transpiration
(d) Fertilization
Ans: (d) Fertilization in plants is not directly influenced by sunlight. It occurs when pollen grains are transported from anthers to stigma. When ripe pollen from an anther catches on the stigma of the same kind of flower, each pollen grain sends out a small threadlike tube. Fertilization occurs after pollination, when pollen grains land on the stigma of a flower of the same species. During this time, a series of events take place leading to the formation of seeds.

Q9. Which of the following is a fish?

(a) Jelly fish (b) Lobster
(c) Salmon (d) Whale
Ans: (c) Salmon is the common name for several species of ray-finned fish in the family Salmonidae. Other fish in the same family include trout, char, grayling and whitefish. Salmon are native to tributaries of the North Atlantic and Pacific Ocean.

Q10. Golden Revolution in India refers to growth of

(a) Militancy in the northeast
(b) Oilseeds production
(c) Horticulture
(d) Increased importing of gold
Ans: (b) The government’s efforts to increase production of fruits, honey and horticultural development is referred to as Golden Revolution. Oil Seeds production is related to Yellow Revolution.

Q11. Which part of brain is also known as “little brain”?

(a) Cerebrum (b) Cerebellum
(c) Thalamus (d) Hypothalamus
Ans: (b) The cerebellum is known as little brain. It is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement- related functions are the most solidly established.

Q12. Which organism is responsible for alcohol fermentation?

(a) Chlorella (b) Yeast
(c) Agaricus (d) Puccinia
Ans: (b) Ethanol fermentation, also called alcoholic fermentation, is a biological process which converts sugars such as glucose, fructose, and sucrose into cellular energy, producing ethanol and carbon dioxide as a side-effect. It is an anaerobic process since Yeasts perform this conversion in the absence of oxygen.

Q13. Global warming is expected to result in

(a) Increase in sea level
(b) Change in crop pattern
(c) Change in coastal line
(d) All of these
Ans: (d) Global Warming is the increase of Earth’s average surface temperature due to effect of greenhouse gases, such as carbon dioxide emissions from burning fossil fuels or from deforestation, which trap heat that would otherwise escape from Earth. It will lead to increase in sea level due to melting of polar ice, desertification leading to changes in crop patters, change in coastal line due to their submergence.

Q14. Silk worms feed on

(a) Basil leaves
(b) Curry leaves
(c) Rose leaves
(d) Mulberry leaves
Ans: (d) Silkworms are the larva of a moth (Bombyx mori) native to Asia that spins a cocoon of fine, strong, lustrous fiber that is the source of commercial silk.Silkworms feed on the leaves of the mulberries (genus Morus) and sometimes on the Osage orange (Maclura pomifera).

Q15. The sexual reproductive organs of aspergillus are :

(a) Spermatium and Oogonium
(b) Antheridium and Oogonium
(c) Spermatium and Ascogonium
(d) Antheridium and Ascogonium
Ans: (d) Sexual reproduction in Aspergillus is rare and takes place in favourable conditions. Sex organs are produced on the same mycelium which has produced conidia. Male organs are called Antheridium or Pollinoduim and female are called archicarp or Ascogonium. Female organs develop as a branch of hypha. The antheridium curves round and bend towards the apex of archicarp as a result of which they become spirally coiled and their tips get fused.

Q16. Which one of the following weeds is effective in controlling water pollution caused by industrial effluents?

(a) Parthenium
(b) Elephant grass
(c) Water hycinth
(d) Mogar grass
Ans: (c) Water hyacinth (Eichhornia crassipes) is used for purifying not only domestic wastewater but also industrial wastewater. It can readily absorb, accumulate and concentrate heavy metals such as lead, cadmium, mercury and nickel. Other studies have evaluated the potential of water hyacinth to absorb various organic chemicals like phenols and toxaphene. Water hyacinth can remove even radioactive metals from industrial effluents, which is very difficult otherwise.

Q17. The tree species most commonly used in social forestry is :

(a) Peepal (b) Gulmohar
(c) Eucalyptus (d) Mango
Ans: (c) Eucalyptus, Acacia, Polar, etc are some of the most commonly used tree species in social forestry. This is because Eucalyptus helps meet increasing wood demands from dwindling natural forests, supplying local communities and industry alike. Eucalyptus first became a component of India’s social forestry program in the 1970s. With financial assistance from the World Bank, large tracts of forest lands, farms, and degraded land in the Indian states of Karnataka, Gujarat, Uttar Pradesh, Punjab and Haryana were planted with eucalyptus.

Q18. The most productive ecosystem in the biosphere is

(a) Desert (b) Open Ocean
(c) Estuary (d) Tundra
Ans: (c) Ecotone regions (transitional zones) like mangroves, wetlands, estuaries, grasslands etc. have far greater productivity compared to natural ecosystems like forest ecosystem, ocean ecosystem, pond ecosystem, riverine ecosystem, desert ecosystem etc. This is because of the wide-ranging species from the adjacent ecosystems being present in the ecotone. Also, an estuary has very little wave action, so it provides a calm refuge from the open sea and hence becomes ideal for the survival of numerous aquatic species. Estuaries are most heavily populated areas throughout the world, with about 60% of the world’s population living along estuaries and the coast.

Q19. One of the best solutions to get rid of non-biodegradable waste is

(a) Burning (b) Dumping
(c) Burying (d) Recycling
Ans: (d) The best way to manage non-biodegradeble wastes such as plastics, metals and electronics is Reduce, Reuse and Recycle. The waste product can be recycled to make it usable again without posing serious challenges to the environment. Recycling is by far the most environmentally friendly option that one can choose.

Q20. Male mosquitoes take their food from

(a) human blood
(b) standing water
(c) sap of plants
(d) dung and debris
Ans: (c) Both male and female mosquitoes eat the same things—nectar, plant sap, or honeydew (a sticky substance excreted by aphids)—for energy. But only female mosquitoes imbibe a blood meal. The females need the protein in blood platelets to develop eggs. Male mosquitoes don’t have specific mouthparts to pierce skin and access blood vessels.

Q21. The specific role of Vitamin K is in the synthesis of

(a) Albumin (b) Antibodies
(c) Globulin (d) Prothrombin
Ans: (d) Vitamin K is a necessary participant in synthesis of several proteins that mediate both coagulation and anticoagulation. It is noteworthy for the synthesis of Prothrombin (coagulation factor II) that forms thrombin in the clotting process. Vitamin K is integrally involved in the clotting mechanism of blood.

Q22. Increased RBC’s in the blood leads to a condition called

(a) Anemia
(b) Haemophilia
(c) Polycythemia
(d) Leukaemia
Ans: (c) Polycythemia is an abnormally high concentration of hemoglobin in the blood through an increase in red cell numbers. People with this condition have thicker blood, which makes it harder for blood to circulate around the body. A relatively stable number of RBCs is maintained in the circulation by increasing or decreasing the rate of production by the bone marrow.

Q23. The liberation of oxygen during photosynthesis is due to

(a) hydrolysis of carbohydrates
(b) photolysis of water
(c) reduction of CO2
(d) breakdown of chlorophyll
Ans: (b) In the process of photosynthesis, oxygen is produced from the photolysis of water. The photolysis of water occurs when light is used to renew split water and adenosine triphosphate, also referred to as ATP. The hydrogen remains in the leaf and participates in further reactions. 2H2O(l) = Hydrogen + O2(g)

Q24. What is the main purpose of white blood corpuscles?

(a) to carry nutrients
(b) to combat infection
(c) to carry oxygen
(d) to give strength
Ans: (b) White blood cells (WBCs), also called leukocytes, are an important part of the immune system. These cells help fight infections by attacking bacteria, viruses, and germs that invade the body. White blood cells originate in the bone marrow, but circulate throughout the bloodstream.

Q25. Siderosis is a disease caused by the inhalation of

(a) silica dust (b) iron dust
(c) zinc dust (d) coal dust
Ans: (b) Siderosis, also known by the name of Welder’s Lung is a pathological condition of the lungs caused by chronic exposure to iron oxide dust, usually at the workplace.Siderosis is considered to be an occupational illness because people breathe in the iron dust at work. The condition usually shows up on Xrays as small, opaque spots on the worker’s lungs.

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