Biology GK Questions Quiz-21

Biology GK Questions Quiz-21

Biology Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Biology for competitive examinations.

    401. For how many years have the dinosaurs been extinct ?

    (1) About 25 million years
    (2) About 65 million years
    Answer:
    401. (2) The Cretaceous-Tertiary mass extinction, which wiped out the dinosaurs and more than half of species on Earth, was caused by an asteroid colliding with Earth and not massive volcanic activity, according to a comprehensive review of all the available evidence, published in the journal Science. A panel of 41 international experts, including UK researchers from Imperial College London, the University of Cambridge, University College London and the Open University, reviewed 20 years’ worth of research to determine the cause of the Cretaceous-Tertiary (KT) extinction, which happened around 65 million years ago. The extinction wiped out more than half of all species on the planet, including the dinosaurs, bird-like pterosaurs and large marine reptiles, clearing the way for mammals to become the dominant species on Earth.

    402. Which phenomenon do bats or dolphins use to find prey, predators or obstacles ?

    (1) Refraction of sound
    (2) Formation of beats
    (3) Scattering of sound
    (4) Echo location
    Answer:
    402. (4) Echolocation, also called biosonar, is the biological sonar used by several kinds of animals. Echolocating animals emit calls out to the environment and listen to the echoes of those calls that return from various objects near them. They use these echoes to locate and identify the objects. Echolocating animals include some mammals and a few birds; most notably microchiro-pteran bats and odontocetes (toothed whales and dolphins), but also in simpler form in other groups such as shrews, one genus of
    megachiropteran bats (Rousettus) and two cave dwelling bird groups, the so-called cave swiftlets in
    the genus Aerodramus (formerly Collocalia) and the unrelated Oilbird Steatornis caripensis.

    403. ‘Cod’ is a variety of

    (1) Goat 
    (2) Fish
    (3) Crop 
    (4) Coral
    Answer:
    403. (2) Cod is the common name for the genus Gadus of demersal fishes, belonging to the family Gadidae. Cod is also used as part of the commons name for a number of other fishes, and there are species suggested to belong to genus Gadus that are not called cod (the Alaska pollock). Cod is popular as a food with a mild flavour and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of vitamin A, vitamin D, vitamin E and omega-3 fatty acids (EPA and DHA). Young Atlantic cod or haddock prepared in strips for cooking is called scrod. In the United Kingdom, Atlantic cod is one of the most common ingredients in fish and chips, along with haddock and plaice.

    404. A large number of identical plants can be obtained in a short span of time through

    (1) large number of seeds of a single plant
    (2) stem cuttings
    (3) tissue culture technique
    (4) hydroponics method
    Answer:
    404. (3) Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation. Plant tissue culture relies on the fact that many plant cells have the ability to regenerate a whole plant (totipotency). The culture medium contains a gel (agar) with the proper mixture of nutrients, sugars, vitamins and hormones, which causes the plant part to grow at very rapid rates to produce new plantlets. It has been estimated that one chrysanthemum apex placed in tissue culture could produce up to 1,000,000 new plantlets in one year. Thus, tissue culture is used for rapid multiplication of plants.

    405. The smallest flowering plant is :

    (1) Wolffia 
    (2) Lemma
    (3) Azolla 
    (4) Ficus
    Answer:
    405. (1) Wolffia is a genus of 9 to 11 species which include the smallest flowering plants on Earth. Commonly called watermeal or duckweed, these aquatic plants resemble specks of cornmeal floating on the water. Wolffia species are free-floating thalli, green or yellowgreen, and without roots. The flower is produced in a depression on the top surface of the plant body. It has one stamen and one pistil. Individuals often float together in pairs or form floating mats with related plants, such as Lemna and Spirodela species. Most species have a very wide distribution across several continents.

    406. Leukaemia or blood cancer is characterised by abnormal increase of the –

    (1) Red blood cells
    (2) White blood cells
    (3) Blood platelets
    (4) Blood plasma
    Answer:
    406. (2) Leukemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called “blasts”. Damage to the bone marrow, by way of displacing the normal bone marrow cells with higher numbers of immature white blood cells, results in a lack of blood platelets, which are important in the blood clotting process. This means people with leukemia may easily become bruised, bleed excessively, or develop pinprick bleeds (petechiae). White blood cells, which are involved in fighting pathogens, may be suppressed or dysfunctional. This could cause the patient’s immune system to be unable to fight off a simple infection or to start attacking other body cells. Because leukemia prevents the immune system from working normally, some patients experience frequent infection, ranging from infected tonsils, sores in the mouth, or diarrhea to life-threatening pneumonia or opportunistic infections. Finally, the red blood cell deficiency leads to anemia, which may cause dyspnea and pallor.

    407. The total number of bones in our body is :

    (1) 226 
    (2) 206
    (3) 256 
    (4) 236
    Answer:
    407. (2) Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue. At birth, there are over 270 bones in an infant human’s body, but many of these fuse together as the child grows, leaving a total of 206 separate bones in an adult. The largest bone in the human body is the femur and the smallest bones are auditory ossicles.

    408. The poison of honey bee is :

    (1) Acidic 
    (2) Alkaline
    (3) Saltish 
    (4) Protein
    Answer:
    408. (1) A bee sting is strictly a sting from a bee (honey bee, bumblebee, sweat bee, etc.). In the vernacular it can mean a sting of a bee, wasp, hornet, or yellow jacket. Bee venom is acidic as it contains the highly acidic peptide melittin, and these interventions are often recommended to neutralize the venom; however, neutralizing a sting is unlikely to be effective as the venom is injected under the skin and deep into the tissues, where a topically applied alkali is unable to reach, so neutralization is unlikely to occur. In any case, the amount of venom injected is typically very small (between 5 and 50 micrograms of fluid) and placing large amounts of alkali near the sting site is unlikely to produce a perfectly neutral pH to stop the pain.

    409. Birds which swim in water have –

    (1) webbed feet
    (2) broad wings
    (3) long beaks
    (4) toes with claws
    Answer:
    409. (1) Almost all the swimming birds have webbed feet which propel them when they are fishing or pursuing a prey into the water. The short legs are situated far towards the lower belly, in order to make easier the swimming action. Flamingos are the exception, gathering both the long legs of the shorebirds and the webbed feet of the ducks. It can feed in deep water and walk easily. Except the Laridae which are more similar to other birds and are able to swim and to walk, all the web-footed birds are very clumsy when they move on the ground. Finally, humans use similar tools when they add flippers to swim faster!

    410. The tallest and thickest type of grass is

    (1) Alfalfa 
    (2) Fodder
    (3) Bamboo 
    (4) Lichens
    Answer:
    410. (3) The bamboo actually belongs to the grass family and is actually the tallest grass of all. There are kinds of bamboo which are said to grow as tall as 100 feet in height. The thickest bamboo can be 0.2m - 0.3m (8-12") thick. Bamboo is a perennial grass with woody stems that are divided into sections by joints called nodes. One of the fastest-growing plants on the planet, bamboo comes in over 1,000 varieties. Plants classified as giant bamboo are the thickest and tallest of the species.

    411. The process of preventing the birds from flying is called

    (1) brailing 
    (2) debeaking
    (3) dubbing 
    (4) pecking
    Answer:
    411. (1) Brailing is the practice of preventing a bird from flying by tying the wing so that it is impossible for the bird to open it fully. The brail is a clear plastic strap, fastened by rivets, which will be used to restrain his wing. Brailing the birds helps prevent injuries during shipment.

    412. Veins seen in the leaves, serve the function of

    (1) Photosynthesis
    (2) Transpiration
    (3) Storage
    (4) Conduction
    Answer:
    412. (4) The veins are the vascular tissue of the leaf and are located in the spongy layer of the mesophyll. They are typical examples of pattern formation through ramification. The pattern of the veins is called venation. The veins are made up of: Xylem: tubes that bring water and minerals from the roots into the leaf; and Phloem: tubes that usually move sap, with dissolved sucrose, produced by photosynthesis in the leaf, out of the leaf. Veins lend support to the leaf tissue, helping it keep its shape, like the ribs of an umbrella help it keep its umbrella shape. They conduct substances within the leaf, rather like the veins in our own bodies conduct blood. So their primary function is the conduction or transportation of nutrients.

    413. The edible part of Cabbage is

    (1) fruit
    (2) condensed flower
    (3) vegetative bud
    (4) inflorescence
    Answer:
    413. (3) In cabbage, the edible part is vegetative bud. Vegetative buds are buds from which vegetative parts like leaves and stems arise, rather than flowers. Enlarged buds or parts of buds form the edible portion of some horticultural crops. Cabbage and head lettuce are examples of unusually large terminal buds.

    414. Which of the following processes are associated with plants during dark period?

    (1) Photosynthesis and respiration
    (2) Respiration and transpiration
    (3) Transpiration and conduction
    (4) Conduction and respiration
    Answer:
    414. (4) Conduction is the process by which vital nutrients are transported to the different parts of a plant. This process is independent of the light factor. Respiration process in plants is the intake of carbon-dioxide and exhales oxygen during the day as the plants gets energy through the photosynthesis process in which the carbon-dioxide is converted into sugars using the sun light energy, as this process uses carbon-dioxide and water, the resulting gas oxygen is given out as a waste product. During the night, as the photosynthesis process cannot be happening without sun, so it exhales the carbon-dioxide itself.

    415. Goitre is caused by the deficiency of

    (1) Iodine 
    (2) Chlorine
    (3) Sodium 
    (4) Calcium
    Answer:
    415. (1) A goitre or goiter is a swelling of the thyroid gland, which can lead to a swelling of the neck or larynx (voice box). Goitre is a term that refers to an enlargement of the thyroid (thyromegaly) and can be associated with a thyroid gland that is functioning properly or not. Worldwide, the most common cause for goitre is iodine deficiency, usually seen in countries that do not use iodized salt. Selenium deficiency is also considered a contributing factor. In countries that use iodized salt, Hashimoto’s thyroiditis is the most common cause.

    416. The total number of biosphere reserves present in India are

    (1) eleven 
    (2) ten
    (3) fifteen 
    (4) twelve
    Answer:
    416. (*) The Indian government has established 18 Biosphere Reserves of India, (categories roughly
    corresponding to IUCN Category V Protected areas), which protect larger areas of natural habitat (than a National Park or Animal Sanctuary), and often include one or more National Parks and/or preserves, along buffer zones that are open to some economic uses. Protection is granted not only to the flora and fauna of the protected region, but also to the human communities who inhabit these regions, and their
    ways of life. Eight of the Eighteen biosphere reserves are a part of the World Network of Biosphere Reserves, based on the UNESCO Man and the Biosphere (MAB) Programme list. In 2009, India designated Cold Desert of Himachal Pradesh as a Biosphere Reserve. And, on September 20, 2010, Ministry of Environment and Forests designated Seshachalam Hills as another Biosphere Reserve taking the count to number of such designated areas to 17. And, on August 25, 2011 Panna (Madhya Pradesh) became India’s 18th Biosphere Reserve.

    417. The green colour of the leaves is due to the presence of

    (1) Proteins
    (2) Lipids
    (3) Chlorophyll
    (4) Carbohydrates
    Answer:
    417. (3) The green color in leaves is caused by the presence of a compound called “chlorophyll,” which the plant produces to do photosynthesis, which is how plants get energy from sunlight. The purpose of chlorophyll is to assist the plant in making food for itself by utilizing energy from sunlight and nutrients from the soil. The chlorophyll is green because it absorbs red and blue wavelengths of light — and so green is not absorbed and is reflected, making the plant look green to our eyes.

    418. The edible part of an onion is

    (1) Modified root
    (2) Aerial flower
    (3) Aerial stem
    (4) Fleshy leaves
    Answer:
    418. (4) Edible plant stems are one part of plants that are eaten by humans. Most plants are made up of roots, stems, leaves, flowers, buds and produce fruits containing seeds. The edible portion in an onion is
    swollen leaves with a bit of stem. They are bulbs which, like garlic and leeks, are modified stems in
    which the primary storage tissue is expanded leaf bases. They come in white, yellow, and red varieties.

    419. To which group of blood an universal recipient belongs?

    (1) A group 
    (2) B group
    (3) 0 group 
    (4) AB group
    Answer:
    419. (4) Type AB+ is the universal recipient. Although those with AB blood type may be referred to as universal recipients, in actuality, type AB+ blood is that of the universal recipient, whereas type AB- is not. This is an important distinction to make.

    420. The normal body temperature of human beings is

    (1) 96.4 °F 
    (2) 97.4 °F
    (3) 98.4 °F 
    (4) 99.4 °F
    Answer:
    420. (3) The normal core body temperature of a healthy, resting adult human being is stated to be at 98.6 degrees fahrenheit or 37.0 degrees celsius. Though the body temperature measured on an individual can vary, a healthy human body can maintain a fairly consistent body temperature that is around the mark of 37.0 degrees celsius. The normal range of human body temperature varies due to an individual’s metabolism rate, the higher (faster) it is the higher the normal body temperature or the slower the metabolic rate the lower the normal body temperature. Other factors that might affect the body temperature of an individual may be the time of day or the part of the body in which the temperature is measured at.

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