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Part 119 – Biology Previous Year Questions

Q1. HIV often changes its shape due to the presence of an enzyme called
(a) Reverse Transcriptase
(b) Enterokinase
(c) Nucleotidase
(d) Nucleoditase
Ans: (a) Use of the reverse transcriptase enzyme is a unique characteristic of retroviruses such as HIV. After the virus releases its genetic material into a host cell, reverse transcriptase converts the viral RNA into a complementary piece of DNA. This process is known as ‘reverse transcription’.

Q2. The cells which are colsely associated and interacting with guard cells are

(a) Transfusion tissue
(b) Complementary cells
(c) Subsidiary cells
(d) Hypodermal cells
Ans: (c) Guard cells interact physiologically and mechanically with subsidiary cells. Guard cells are those which have chloroplasts and control the opening of stomata. But, subsidiary cells are those which support the guard cells and they do not have chloroplasts.

Q3. Conversion of starch to sugar is essential for

(a) Stomatal opening
(b) Stomatal closing
(c) Stomatal formation
(d) Stomatal growth
Ans: (a) For keeping the stomata open a constant expenditure of energy is required. This is provided by the conversion of starch to sugar. The stomatal opening is, in turn, related to transpiration which is the evaporation of water from plants. It occurs chiefly at the leaves while their stomata are open for the passage of CO2 and O2 during photosynthesis.

Q4. Which of the following Genetically Modified vegetable is recently being made available in Indian market ?

(a) Carrot (b) Radish
(c) Brinjal (d) Potato
Ans: (*) Bt cotton is the only commercially available genetically modified (GM) crop in India (The Guardian, 31 July 2014). When Bt Brinjal was sought to be introduced in the market a few years ago, it led to a controversy. The Ministry of Environment and Forests imposed a moratorium on Bt Brinjal on February 9, 2010.

Q5. Which of the following listed is not a feature of organic farming ?

(a) The non-use of chemical fertilizers and pesticides
(b) Soil is nurtured for furture use by maintaining micro-organisms
(c) Use of synthetic fertilizers
(d) Very less energy consumption
Ans: (c) Organic farming is a form of agriculture that relies on techniques such as crop rotation, green manure, compost, and biological pest control. It uses fertilizers and pesticides if they are considered natural (such as bone meal from animals or pyrethrin from flowers), but it excludes the use of synthetic petrochemical fertilizers and pesticides, plant growth regulators, etc.

Q6. The main function of palisade parenchyma in leaf is

(a) Antibiotics (b) Pollutants
(c) Hormones (d) Toxins
Ans: (d) Palisade parenchyma is the layer of tissue directly beneath the epidermis of the upper surface of a leaf. It contains the cylinder-shaped cells that hold the chloroplasts and constitutes the primary area of photosynthesis that converts the light energy to the chemical energy of carbohydrates

Q7. The harmful substances produced by the microbes are known as

(a) Antibiotics (b) Pollutants
(c) Hormones (d) Toxins
Ans: (d) Toxins are substances created by plants and animals that are poisonous to humans. Most toxins that cause problems in humans are released by microorganisms such as bacteria, viruses, fungi, rickettsiae or protozoa. For example, cholera is due to a bacterial toxin.

Q8. For immediate energy production in cells, one should take

(a) Glucose (b) Proteins
(c) Vitamin C (d) Sucrose
Ans: (a) Glucose provides immediate energy for our brain and red blood cells. The most pressing need of all cells in the body is for an immediate source of energy. Some cells such as brain cells have severely limited storage capacities for either glucose or ATP, and for this reason, the blood must maintain a fairly constant supply of glucose.

Q9. In human body, ligaments are made up of

(a) white fibres and some yellow elastic fibres
(b) white fibres only
(c) yellow fibres only
(d) yellow fibres and muscle fibres
Ans: (a) A ligament is composed of dense fibrous bundles of collagenous fibres and spindle-shaped cells known as fibrocytes, with little ground substance. Ligaments may be of two major types: white ligament is rich in collagenous fibres, which are sturdy and inelastic; and yellow ligament is rich in elastic fibres, which are quite tough even though they allow elastic movement.

Q10. Which one of the following types of malaria is pernicious malaria ?

(a) Vivax (b) Ralapse
(c) Tertian (d) Malignant
Ans: (d) Pernicious malaria is always caused by Plasmodium falciparum and characterized by severe malarial paroxysms that recur about every 48 hours and often by acute cerebral, renal, or gastrointestinal manifestations. It is also called malignant tertian malaria.

Q11. Lungs of a plant are

(a) Leaves (b) Stems
(c) Flowers (d) Roots
Ans: (a) Leaves are the lungs of plants. Much like the lungs of animals, leaves are the place of a plant’s respiration. It is from leaves that oxygen is emitted during the light hours of the day and carbonic acid gas at night.

Q12. Sporangia bearing leaf of a fern is called

(a) Ramentum (b) Indusium
(c) Sorus (d) Sporophyll
Ans: (c) The Sporangia are the reproductive structures of the ferns and fern allies. They are miniature sacks or capsules that produce the dust-like spores that are the “seeds” by which ferns are propagated. Several sporangia grouped together are called a Sorus.

Q13. ‘Coralloid root’ of Cycas helps in

(a) Absorption of water
(b) Absorption of water and fixation of Nitrogen
(c) Anchorage
(d) Transport of food
Ans: (b) Branch roots are of two kinds: long-branching geotropic roots and short-branching apogeotropic roots, which are referred to as coralloid because of their irregular, beady appearance. The coralloid roots contain symbiotic cyanobacteria (blue-green algae), which fix nitrogen. It also collects water and soil nutrients and store carbohydrates.

Q14. Water conduction takes place in mosses through

(a) Xylem and Phloem
(b) Xylem
(c) Collenchyma
(d) Parenchyma
Ans: (d) Botanically, mosses are non-vascular plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide and sunlight to create food by photosynthesis. They have no vascular system to transport water. They do not have a well-developed xylem. Their conducting tissue is made up of parenchyma.

Q15. Companion cells of phloem are found in

(a) Gymnosperms
(b) Bryophyta
(c) Pteridophyta
(d) Angiosperms
Ans: (d) Only in angiosperms are sieve tubes and companion cells found in the phloem. In other vascular plants, parenchyma cells function in the same way as companion cells (that is, as the sieve cell’s living protoplasm), but they are not derived from the same mother cell as the sieve element.

Q16. A clone is a group of individuals obtained through

(a) Hybridisation
(b) Micropropagation
(c) Cross pollination
(d) Self pollination
Ans: (b) Micropropagation is the practice of rapidly multiplying stock plant material to produce a large number of progeny plants, using modern plant tissue culture methods. It leads to the production of plants that are clones of each other. It often produces more robust plants, leading to accelerated growth compared to similar plants produced by conventional methods – like cuttings.

Q17. What does the word ‘amphibian’ means ?

(a) Three lives (b) Four lives
(c) Two lives (d) One lives
Ans: (c) The word amphibian means two-lives. Amphibians spend their lives in the water and on land. All amphibians begin their life in water with gills and tails; as they grow, they develop lungs and legs for their life on land. Members of this animal class are frogs, toads, etc.

Q18. Interferons are synthesized in response to

(a) Bacteria (b) Fungi
(c) Mycoplasma(d) Virus
Ans: (d) Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of pathogens, such as viruses, bacteria, parasites, or tumor cells. Interferon synthesis occurs primarily in response to viral single-stranded or double stranded RNA that are either the genetic material of RNA viruses or a product of viral transcription. Interferons are named for their ability to “interfere” with viral replication by protecting cells from virus infections.

Q19. The resources which are obtained from bio sphere and have life are :

(a) Potential resources
(b) Biotic resources
(c) Abiotic resources
(d) Renewable resources
Ans: (b) Biotic resources describe living or once living resources of a community; for example organisms, such as plants and animals. They are obtained from the biosphere and have life. The resources which are composed of non-living things are called Abiotic Resources. For example, water, minerals, metals, wind, solar energy etc.

Q20. The hydrophilic nature of DNA is due to the presence of :

(a) thymine base
(b) a number of hydrogen bonds
(c) phosphate group
(d) deoxyribose sugar
Ans: (b) The phosphate groups on DNA are ionic and charged. Each phosphate group on the DNA backbone is one unit of negative charge (-1). Charged molecules attract water and are hydrophilic. DNA has two hydrophilic polar external backbones made of sugars and phosphate groups joined by ester bonds.

Q21. Which of the following is used in the treatment of cancer ?

(a) Physiotherapy
(b) Chemotherapy
(c) Electrotherapy
(d) Psychotherapy
Ans: (b) Chemotherapy (or CTX) is a category of cancer treatment that uses chemical substances, especially one or more anti-cancer drugs (chemotherapeutic agents) that are given as part of a standardized chemotherapy regimen. Traditional chemotherapeutic agents are cytotoxic, that is to say they act by killing cells that divide rapidly, one of the main properties of most cancer cells.

Q22. Red rot of sugarcane is caused by :

(a) Alternaria alternata
(b) Phylophthora infestans
(c) Colletotrichum falcatum
(d) Cercospora personata
Ans: (c) Red rot disease is caused by the fungus Glomerella tucumanensis. An older name, Colletotrichum falcatum, is still preferred by some pathologists. Red rot occurs in various parts of the cane plant but it is usually considered a stalk and a seed-piece disease. Its symptoms are highly variable depending upon the susceptibility of the sugarcane variety and the environment.

Q23. The fleshy thalamus is edible in

(a) Apple (b) Tomato
(c) Orange (d) Mango
Ans: (a) Apple is a pome, a simple, fleshy but false fruit as it is surrounded by a fleshy thalamus which is edible while actual fruit lies within. Other examples are pear, loquat, etc.

Q24. The sense of balance is achieved by :

(a) Cerebrum equilibrium
(b) Thalamus equilibrium
(c) Cerebellum equilibrium
(d) Spinal chord equilibrium
Ans: (c) The cerebellum equilibrium controls the aspects of balance, equilibrium, and muscle tone, which are factors that provide for smooth movement and activity. Electrical impulses from the cerebellum stimulate muscles that are responsible for voluntary movement, and it works in coordination with the motor cortices of the cerebrum for this overall function.

Q25. What does the word ‘amphibian’ means ?

(a) Three lives (b) Four lives
(c) Two lives (d) One lives
Ans: (c) The word amphibian means two-lives. Amphibians spend their lives in the water and on land. All amphibians begin their life in water with gills and tails; as they grow, they develop lungs and legs for their life on land. Members of this animal class are frogs, toads, etc.

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