Biology GK Questions Quiz-28

Biology GK Questions Quiz-28

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

    541. In onion food is stored in

    (1) aerial stem 
    (2) root
    (3) scale leaves
    (4) bud
    Answer:
    541. (3) In onions, the bulbs consist of very short stems with closely packed leaves arranged in concentric circles round the stem. These leaves are swollen with stored food. The inner leaves are fleshy while the outer ones are dry. This is called as tunicated bulb since the concentric leaf bases form a complete covering or tunic.

    542. The reagent used to test the presence of starch in leaves is

    (1) Fehling’s solution
    (2) Iodine solution
    (3) Million’s reagent
    (4) Benedict’s solution
    Answer:
    542. (2) The Iodine test is used to test for the presence of starch. Iodine solution — iodine dissolved in an aqueous solution of potassium iodide — reacts with the starch producing a purple black color.

    543. Malaria can be cured with a drug extracted from

    (1) Belladonna tree
    (2) Cinchona tree
    (3) Oak tree
    (4) Neem tree
    Answer:
    543. (2) Quinine, as a component of the bark of the cinchona tree, was used to treat malaria from as early as the 1600s. The bark of trees in this genus is the source of a variety of alkaloids, the most familiar of which is quinine, an antipyretic (anti-fever) agent.

    544. Which of the following provides energy for photosynthesis?

    (1) Water
    (2) Sunlight
    (3) Chlorophyll
    (4) Carbon dioxide
    Answer:
    544. (2) Photosynthesis is a process used by plants and other organisms to convert the light energy captured from the sun into chemical energy that can be used to fuel the organism's activities. The general equation for photosynthesis is therefore: Carbon dioxide + electron donor + light energy ® carbohydrate + oxidized electron donor.

    545. Food for the developing foetus is supplied by the

    (1) Uterus 
    (2) Placenta
    (3) Ovary 
    (4) Allantosis
    Answer:
    545. (2) The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient
    uptake, waste elimination, and gas exchange via the mother's blood supply. It allows the transfer of
    nutrients and oxygen from the mother to the fetus and the transfer of waste products and carbon dioxide
    back from the fetus to the maternal blood supply. Nutrient transfer to the fetus occurs via both active
    and passive transport.

    546. The importance of perspiration is to

    (1) Eliminate body odours
    (2) Improve the general health
    (3) Open the pores in the skin
    (4) Regulate body temperature
    Answer:
    546. (4) The human body regulates temperature by keeping a tight balance between heat gain and heat loss. The hypothalamus responds to various temperature receptors located throughout the body and makes physiological adjustments to maintain a constant core temperature. Perspiration lowers body temperature when sweat evaporates, since conversion of liquid water to gaseous form takes energy.

    547. A disease caused by fungus is

    (1) Round worm
    (2) Ringworm
    (3) Tapeworm
    (4) Filaria
    Answer:
    547. (2) Dermatophytosis or ringworm is a clinical condition caused by fungal infection of the skin in humans, pets such as cats, and domesticated animals such as sheep and cattle. The fungi that cause parasitic infection feed on keratin, the material found in the outer layer of skin, hair, and nails.

    548. How many times does the heart beat approximately in a minute in humans?

    (1) 25 times 
    (2) 30 times
    (3) 72 times 
    (4) 96 times
    Answer:
    548. (3) The average heart rate for adult humans is about 70 to 75 beats per minute in a normal relaxed mode. The "normal" heart beat rate is taken to be "72 beats per minute”.

    549. Protein is considered as a

    (1) Body builder
    (2) Energy producer
    (3) Regulator
    (4) Bulk increaser
    Answer:
    549. (1) Protein is required by the body for the growth, maintenance and repair of all cells. Protein is a major component of all muscles, tissues and organs and is vital for practically every process that occurs within the body such as metabolism, digestion and the transportation of nutrients and oxygen in the blood. When the proteins that we consume in our food are broken down through digestion into individual amino acids, these amino acids are then absorbed and reform in order to create new proteins that are then used by the body.

    550. In test-tube babies, the

    (1) Ovum is fertilized and developed in test-tubes
    (2) Ovum is fertilized in the testtubes and developed in uterus
    (3) Ovum is fertilized in the uterus and developed in testtubes
    (4) Ovum is developed without fertilization in test-tubes
    Answer:
    550. (2) In vitro fertilization is a process by which an egg is fertilized by sperm outside the body. The process involves monitoring a woman's ovulatory process, removing ovum or ova (egg or eggs) from the woman's ovaries and letting sperm fertilize them in a fluid medium in a laboratory. The fertilized egg (zygote) is then transferred to the patient's uterus with the intention of establishing a successful pregnancy.

    551. Rabies is caused by

    (1) bacteria 
    (2) virus
    (3) fungus 
    (4) algae
    Answer:
    551. (2) Rabies is a viral disease that causes acute encephalitis in warm-blooded animals. The disease
    is zoonotic, meaning it can be transmitted from one species to another, such as from dogs to humans,
    commonly by a bite from an infected animal.

    552. Which of the following is the best source of Iodine?

    (1) Algae 
    (2) Beans
    (3) Radish 
    (4) Wheat
    Answer:
    552. (2) Iodine exists in soil, but the content may vary because soil erosion can leach away this and other minerals. Beans and seeds highest in iodine content include lima beans, soybeans, cooked navy beans and sesame seeds. Vegetables highest in iodine include spinach, Swiss chard, turnip greens, summer squash and white potatoes with the peel. The herb highest in iodine is garlic.

    553. Transport of oxygen by blood takes place with the help of

    (1) Erythrocytes
    (2) Thrombocytes
    (3) Lymphocytes
    (4) Leucocytes
    Answer:
    553. (1) Red blood cells, or erythrocytes, are the most common type of blood cell and the vertebrate
    organism's principal means of delivering oxygen (O2) to the body tissues via the blood flow through the
    circulatory system. The cytoplasm of these cells is rich in haemoglobin, an iron-containing bio-molecule that can bind oxygen and is responsible for the blood's red color.

    554. In a plant, the xylem tissue conducts :

    (1) water
    (2) food
    (3) water and food
    (4) None of these
    Answer:
    554. (1) Xylem is of a plant's vascular system that conveys water and dissolved minerals from the roots to the rest of the plant and furnishes mechanical support. It constitutes the major part of a mature woody stem or root and the wood of a tree, and consists of specialized water-conducting tissues made up mostly of several types of narrow, elongate, hollow cells.

    555. The gas released during photosynthesis :

    (1) Carbon dioxide
    (2) Oxygen
    (3) Carbon monoxide
    (4) Sulphur dioxide
    Answer:
    555. (2) In plants, algae, and cyanobacteria, photosynthesis uses carbon dioxide and water, releasing oxygen as a waste product. Photosynthesis is vital for all aerobic life on Earth. In oxygenic photosynthesis water is the electron donor and, since its hydrolysis releases oxygen, the equation for this process is: Carbon dioxide + Water + Light energy ® Carbohydrate + Oxygen + Water

    556. Carrot is a rich source of vitamin

    (1) A 
    (2) C
    (3) D 
    (4) E
    Answer:
    556. (1) Carrot is an extremely rich source of vitamin A. The name carotene, which is a form of pro-vitamin, has been derived from carrot. The carotene is converted into vitamin A by the liver and it is also stored in our body.

    557. Which one of the following is used as a food preservative ?

    (1) Sodium benzoate
    (2) Sodium thiosulphate
    (3) Sodium hydroxide
    (4) Sodium bicarbonate
    Answer:
    557. (1) Sodium benzoate has the chemical formula NaC6H5CO2; it is a widely used food preservative,
    with E number E211. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid.

    558. Cellulose is the chief constituent of

    (1) cell wall
    (2) cell membrane
    (3) secondary wall of xylem
    (4) body wall of insects
    Answer:
    558. (1) In the primary (growing) plant cell wall, the major carbohydrates are cellulose, hemicellulose and pectin. The cell wall in plants provides the most significant difference between plant cells and other eukaryotic cells. The cell wall is rigid (up to many micrometers in thickness) and gives plant cells a much defined shape.

    559. Which of the following events occurred first ?

    (1) DNA structure of genes was discovered by James D Watson and Francis Crick
    (2) Yuri Gagarin became the first man in space
    (3) World’s first human heart transplant was performed by Dr. Christian Barnard
    (4) World’s first test tube baby Louise Brown was born in U.K.
    Answer:
    559. (1) Discovery of DNA structure of genes: 25 April, 1953; Yuri Gagarin's feat of becoming the first man in space: 12 April, 1961; World's first human heart transplant: 3 December, 1967; and World's first test tube baby: 25 July, 1978.

    560. The biological death of a patient means the death of tissues of the

    (1) kidney 
    (2) heart
    (3) brain 
    (4) lungs
    Answer:
    560. (3) Biological death occurs when brain cells start to die due to lack of oxygen. Biological death follows clinical death (when a person stops breathing). Without oxygen brain damage can occur within
    minutes. 4-6 minutes of oxygen deprivation can cause minor brain damage. 6-10 minutes of oxygen
    deprivation will cause brain damage. After 10 minutes of no oxygen irreversible brain damage occurs.

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