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Part 081 – Biology Previous Year Questions

Q1. The seeds of certain plants fail to germinate if they do not pass through the digestive tract of fruit-eating birds. This is due to
(a) hibernation
(b) seed coat impermeability
(c) infertility
(d) vegetative reproduction
Ans: (b) A dormant seed is one that is unable to germinate in a specified period of time under a combination of environmental factors that are normally suitable for the germination of the non-dormant seed. Dormancy is a mechanism to prevent germination during unsuitable ecological conditions, but the probability of seedling survival is low. Dormancy that is caused by an impermeable seed coat is known as physical dormancy. Physical dormancy is the result of impermeable layer(s) that develops during maturation and drying of the seed or fruit. This impermeable layer prevents the seed from taking up water or gases. As a result, the seed is prevented from germinating until dormancy is broken.

Q2. Sucrose content in sugarcane decreases

(a) if high rainfall occurs during the period of growth of the plant
(b) if frost occurs during the period of ripening
(c) if there is fluctuation in temperature during the period of growth of the plant
(d) if there is high temperature during the time of ripening
Ans: (b) Once cut, sugarcane begins to lose its sugar content, and damage to the cane during mechanical harvesting accelerates this decline. Sugarcane is cultivated in the tropics and subtropics in areas with plentiful supply of water, for a continuous period of more than six to seven months each year, either from natural rainfall or through irrigation. The crop does not tolerate severe frosts. Therefore, most of the world’s sugarcane is grown between 22°N and 22°S, and some up to 33°N and 33°S. Sugarcane requires a fairly dry, sunny and cool, but frost free season for ripening and harvesting – moisture percentage drops steadily throughout the life of the sugarcane plant, from 83% in very young cane to 71% in mature cane, meanwhile sucrose grows from less than 10 to more than 45% of the dry weight.

Q3. Animals having open circulatory system possesses :

(a) coelenteron (b) spongocoel
(c) pseudocoel (d) haemocoel
Ans: (d) Open circulatory system is the one in which blood does not circulate only inside blood vessels but it also falls in cavities that irrigate tissues. The internal organs are suspended in a network of blood-filled sinuses or open spaces which collectively form the haemocoel.

Q4. The concept of ‘survival of the fittest’ was first advocated by

(a) Oparin (b) Darwin
(c) Spencer (d) Haeckel
Ans: (b) “Survival of the fittest” is a phrase originating in evolutionary theory, as an alternative description of natural selection. The phrase is today commonly used in contexts that are incompatible with the original meaning as intended by its first two proponents: British polymath philosopher Herbert Spencer (who coined the term) and Charles Darwin. Herbert Spencer first used the phrase – after reading Charles Darwin’s On the Origin of Species – in his Principles of Biology (1864), in which he drew parallels between his own economic theories and Darwin’s biological ones. Darwin first used Spencer’s new phrase “survival of the fittest” as a synonym for natural selection in the fifth edition of On the Origin of Species, published in 1869.

Q5. Deficiency of vitamin D in children causes

(a) beriberi (b) pellagra
(c) rickets (d) scurvy
Ans: (c) Rickets is a softening of bones in children due to deficiency or impaired metabolism of vitamin D, phosphorus or calcium, potentially leading to fractures and deformity. Rickets is among the most frequent childhood diseases in many developing countries. The predominant cause is a vitamin D deficiency, but lack of adequate calcium in the diet may also lead to rickets (cases of severe diarrhea and vomiting may be the cause of the deficiency). Although it can occur in adults, the majority of cases occur in children suffering from severe malnutrition, usually resulting from famine or starvation during the early stages of childhood.

Q6. In man, the normal number of chromosomes is

(a) 42 (b) 44
(c) 46 (d) 48
Ans: (c) Chromosomes are the structures that hold our genes. Genes are the individual instructions that tell our bodies how to develop and function; they govern our physical and medical characteristics, such as hair color, blood type and susceptability to disease. The typical number of chromosomes in a human cell is 46 – two pairs of 23 – holding an estimated 25,000 genes. One set of 23 chromosomes is inherited from the biological mother (from the egg), and the other set is inherited from the biological father (from the sperm).

Q7. Scurvy is a disease which is caused due to the deficiency of vitamin

(a) A (b) K
(c) C (d) B12
Ans: (c) Scurvy is a condition where an individual has a vitamin C (ascorbic acid) deficiency. Scurvy often presents itself initially as symptoms of malaise and lethargy, followed by formation of spots on the skin, spongy gums, and bleeding from the mucous membranes. Spots are most abundant on the thighs and legs, and a person with the ailment looks pale, feels depressed, and is partially immobilized. As scurvy advances, there can be open, suppurating wounds, loss of teeth, jaundice, fever, neuropathy and death. Scurvy was at one time common among sailors, pirates and others aboard ships at sea longer than perishable fruits and vegetables could be stored (subsisting instead only on cured and salted meats and dried grains) and by soldiers similarly separated from these foods for extended periods.

Q8. Respiration is

(a) oxidation (b) reduction
(c) hydrolysis (d) amination
Ans: (a) Cellular respiration allows organisms to use (release) energy stored in the chemical bonds of glucose (C6H12O6). The energy in glucose is used to produce ATP. Cells use ATP to supply their energy needs. Cellular respiration is therefore a process in which the energy in glucose is transferred to ATP. C6H12O6+ 602——6CO2+ 6H2O+ energy (36 ATP). In respiration, glucose is oxidized and thus releases energy. Oxygen is reduced to form water. The carbon atoms of the sugar molecule are released as carbon dioxide (CO2).

Q9. During photosynthesis green plants absorb

(a) nitrogen
(b) carbon dioxide
(c) carbon monoxide
(d) oxygen
Ans: (b) Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar. This process occurs in plants and some algae (Kingdom Protista). Plants need only light energy, CO2, and H2O to make sugar. The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis. Photosynthesis takes place primarily in plant leaves, and little to none occurs in stems, etc. The parts of a typical leaf include the upper and lower epidermis, the mesophyll, the vascular bundle(s) (veins), and the stomates. The upper and lower epidermal cells do not have chloroplasts, thus photosynthesis does not occur there. They serve primarily as protection for the rest of the leaf. The stomates are holes which occur primarily in the lower epidermis and are for air exchange: they let CO2 in and O2 out.

Q10. Tamiflu is frontline drug against

(a) bird flu (b) cancer
(c) AIDS (d) polio
Ans: (a) Oseltamivir marketed under the trade name Tamiflu, is an antiviral drug, which may slow the spread of influenza (flu) virus between cells in the body by stopping the virus from chemically cutting ties with its host cell. The drug is taken orally in capsules or as a suspension. It has been used to treat and prevent influenza A virus and influenza B virus infection in over 50 million people since 1999.

Q11. ‘Why excessive heating and repeated use of cooking oil are most undesirable ?

(a) The oil vapour can cause indoor pollution
(b) Carcinogenic substances like benzpyrene are produced
(c) Nutrient value of food is lost
(d) Loss and wastage of oil
Ans: (b) Repeated use of cooking oil at high temperatures will cause the hydraulic fat into free fatty acids are easily oxidized, so that the oil becomes rancid and form trans fatty acids can lead to health problems associated with the metabolism of cholesterol, high blood pressure, and heart. Not only that, the repeated use of used oil will also form acrolein is a compound that causes intense itching in the throat and cause coughing. And that is not less dangerous, this oil is a carcinogen that can cause cancer. Therefore, experts recommend eating foods that contain saturated fat less than 10 percent of the daily intake.

Q12. The name of the first cloned sheep was

(a) Molly (b) Dolly
(c) Jolly (d) Roly
Ans: (b) Dolly was a female domestic sheep, and the first mammal to be cloned from an adult somatic cell, using the process of nuclear transfer. She was cloned by Ian Wilmut, Keith Campbell and colleagues at the Roslin Institute and the biotechnology company PPL Therapeutics near Edinburgh in Scotland. The cell used as the donor for the cloning of Dolly was taken from a mammary gland, and the production of a healthy clone therefore proved that a cell taken from a specific part of the body could recreate a whole individual.

Q13. Through ‘Photosynthesis’ green plants generate

(a) inorganic materials
(b) minerals
(c) organic materials
(d) nutrients
Ans: (c) Photosynthesis is the process by which green plants and certain other organisms transform light energy into chemical energy. Photosynthesis in green plants harnesses the energy of sunlight to convert carbon dioxide, water, and minerals into organic compounds and gaseous oxygen. The principal organic products of plant photosynthesis are carbohydrates. Formation of the simple carbohydrate glucose is shown by the equation: 6CO2 (carbon dioxide) + 12H2O (water) C6H12O6 (glucose) + 6O2 (oxygen) + H2O (water).

Q14. Lac is produced from

(a) a tree (b) an insect
(c) an cat (d) a muskrat
Ans: (b) Lac is the scarlet resinous secretion of a number of species of insects, namely some of the species of the genera Metatachardia, Laccifer, Tachordiella, Austrotacharidia, Afrotac-hardina, and Tachardina of the superfamily Coccoidea, of which the most commonly cultivated species is Kerria lacca. The above-mentioned families are some of the 28 families of scale insects and mealybugs comprising a large group of about 8,000 described species of plant sucking insects, a few of which produce similar natural products (e.g., cochineal and crimson). Thousands of these tiny insects colonize branches of suitable host trees and secrete the resinous pigment. The coated branches of the host trees are cut and harvested as sticklac.

Q15. Quarantine regulation is concerned with

(a) growing of better varieties of plant
(b) prevention of entry of diseased organism
(c) spraying of insecticide over diseased plants
(d) identification of diseased organism
Ans: (b) Quarantine is compulsory isolation, typically to contain the spread of something considered dangerous, often but not always disease. Quarantine legislation is in place in countries worldwide restricting the import of non-indigenous plant and animal pathogens. Those who wish to import such organisms must hold the relevant import permit, which can be obtained, from the relevant country Authority.

Q16. Toxicology is related to the study of

(a) viruses (b) bacteria
(c) diseases (d) poisons
Ans: (d) Toxicology is the study of the adverse effects of chemicals on living organisms. It is the study of symptoms, mechanisms, treatments and detection of poisoning, especially the poisoning of people. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. The chief criterion regarding the toxicity of a chemical is the dose, i.e. the amount of exposure to the substance. All substances are toxic under the right conditions. The term LD50 refers to the dose of a toxic substance that kills 50 percent of a test population (typically rats or other surrogates when the test concerns human toxicity).

Q17. Which of the following hormones is released in excess quantity during excitement ?

(a) Cortisone (b) Serotonin
(c) Adrenaline (d) Oestrogen
Ans: (c) Adrenaline is a hormone produced by the adrenal glands during high stress or exciting situations. This powerful hormone is part of the human body’s acute stress response system, also called the “fight or flight” response. It works by stimulating the heart rate, contracting blood vessels, and dilating air passages, all of which work to increase blood flow to the muscles and oxygen to the lungs. Additionally, it is used as a medical treatment for some potentially life-threatening conditions including anaphylactic shock. In the US, the medical community largely refers to this hormone as epinephrine, although the two terms may be used interchangeably.

Q18. Scientific study of birds is known as

(a) Limnology (b) Herpetology
(c) Malacology (d) Ornithology
Ans: (d) Ornithology is a branch of zoology that concerns the study of birds. The science of ornithology has a long history and studies on birds have helped develop several key concepts in evolution, behaviour and ecology such as the definition of species, the process of speciation, instinct, learning, ecological niches, guilds, island biogeography, phylogeo-graphy and conservation.

Q19. Which one of the following is a non-poisonous snake ?

(a) Cobra (b) Dryophis
(c) Elapes (d) Python
Ans: (d) Pythonidae, commonly known simply as pythons, from the Greek word python, is a family of nonvenomous snakes found in Africa, Asia and Australia. Among its members are some of the largest snakes in the world. Pythons are found in sub-Saharan Africa, Nepal, India, Burma, southern China, Southeast Asia and from the Philippines southeast through Indonesia to New Guinea and Australia.

Q20. Which among the following is used in the treatment of tuberculosis ?

(a) Penicillin (b) Aspirin
(c) Paracetamol(d) Dettol
Ans: (a) In the past 60 years, antibiotics have been critical in the fight against infectious disease caused by bacteria and other microbes. In 1946, penicillin became generally available for treatment of bacterial infections, especially those caused by staphylococci and streptococci. Initially, the antibiotic was effective against all sorts of infections caused by these two Gram-positive bacteria. Penicillin had unbelievable ability to kill these bacterial pathogens without harming the host that harbored them. It is important to note that a significant fraction of all human infections are caused by these two bacteria (i.e., strep throat, pneumonia, scarlet fever, septicemia, skin infections, wound infections, etc.). In the late 1940s and early 1950s, new antibiotics were introduced, including streptomycin, chloramphenicol and tetracycline, and the age of antibiotic chemotherapy came into full being. These antibiotics were effective against the full array of bacterial pathogens including Gram-positive and Gram-negative bacteria, intracellular parasites, and the tuberculosis bacillus. Synthetic antimicrobial agents such as the “sulfa drugs” (sulfonamides) and anti-tuberculosis drugs, such as para aminosalicylic acid (PAS) and isoniazid (INH), were also brought into wider usage. At present, tuberculosis treatment does not involve the usage of penicillin. The drugs used in the tratment of tuberculosis are ethambutol, isoniazid, rifampicin, etc.

Q21. Which part of human body is first highly affected by nuclear radiation ?

(a) Eyes
(b) Lungs
(c) Skin
(d) Bone Marrow
Ans: (c) When molten nuclear fuel melts through a nuclear power plant’s barriers, it causes a serious radiation leak. The radioactive materials will seep out to the surrounding environment, and into the air. Once in the upper atmosphere, high winds and jet streams could carry the dust to all places, and dropping radiation on everything, causing radiation poisoning. Radiation can penetrate deep inside the human body, and into the cells. Certain body parts are more specifically affected by exposure to different types of radiation sources. The areas of skin exposed to radiation will appear like severe sunburn, then sores may form, and skin infection may develop.

Q22. Olive Ridley is a famous

(a) cricketer
(b) turtle species
(c) grass type vegetation
(d) Another name for olive tree
Ans: (b) The Olive Ridley is considered the most abundant sea turtle in the world, with an estimated 800,000 nesting females annually. The Olive Ridley gets its name from the olive coloration of its heart-shaped top shell (carapace). The Olive Ridley has one of the most extraordinary nesting habits in the natural world. Large groups of turtles gather off shore of nesting beaches. Then, all at once, vast numbers of turtles come ashore and nest in what is known as an “arribada”. During these arribadas, hundreds to thousands of females come ashore to lay their eggs. The Olive Ridley turtles are the smallest and most abundant of all sea turtles found in the world, inhabiting warm waters of the Pacific, Atlantic and Indian oceans.

Q23. The standard audible capacity of a healthy human being as per World Health Organi-sation is in the range of

(a) 45-50 decibels
(b) 200-250 decibels
(c) 5-10 decibels
(d) 2000-2500 decibels
Ans: (c) Hearing range usually describes the range of frequencies that can be heard by an animal or human, though it can also refer to the range of levels. In humans the audible range of frequencies is usually said to be 20 Hz (cycles per second) to 20 kHz (20,000 Hz), although there is considerable variation between individuals, especially at the high frequency end, where a gradual decline with age is considered normal. Specifically, humans have a maximum aural range that begins as low as 12 Hz under ideal laboratory conditions, to 20 kHz in most children and some adults, but the range shrinks during life, usually beginning at around the age of 8 with the higher frequencies fading. Inaudible sound waves can be detected (felt) by humans through physical body vibration in the range of 4 to 16 Hz.

Q24. Jonas Salk invented the vaccine for

(a) Polio (b) Hepatitis
(c) Typhoid (d) Cholera
Ans: (a) Jonas Edward Salk was an American medical researcher and virologist, best known for his discovery and development of the first polio vaccine. The field trial set up to test the vaccine developed by Salk and his research team was the most elaborate program of its kind in history, involving 20,000 physicians and public health officers, 64,000 school personnel, and 220,000 volunteers,” with over 1,800,000 school children participating in the trial. On April 12, 1955, Dr. Thomas Francis, Jr., of the University of Michigan, the monitor of the test results, “declared the vaccine to be safe and effective.”

Q25. Cancer is a disease where we find uncontrolled

(a) cell division
(b) cell swelling
(c) cell inflammation
(d) cell deformity
Ans: (a) Cancer is the uncontrolled growth of abnormal cells in the body. Cancerous cells are also called malignant cells. Symptoms of cancer depend on the type and location of the cancer. Cancer grows out of normal cells in the body. Normal cells multiply when the body needs them, and die when the body doesn’t need them. Cancer appears to occur when the growth of cells in the body is out of control and cells divide too quickly. It can also occur when cells forget how to die. The most common cause of cancer-related death is lung cancer.

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