Biology GK Questions Quiz-25

Biology GK Questions Quiz-25

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

    481. Jaundice is caused due to the infection of

    (1) brain 
    (2) liver
    (3) kidney 
    (4) spleen
    481. (2) Jaundice is a yellow discoloration of the skin, mucous membranes, and the whites of the eyes
    caused by increased amounts of bilirubin in the blood. Normally, the liver metabolizes and excretes the
    bilirubin in the form of bile. However, if there is a disruption in this normal metabolism and/or production of bilirubin, jaundice may result.

    482. The protein present in the finger nail is

    (1) Actin 
    (2) Myosin
    (3) Globin 
    (4) Keratin
    482. (4) Keratin is a fibrous protein making up most cells found in our nails and hair and the epidermis layer of our skin. It also makes up fish scales and crustacean shells, bird feathers and beaks, and
    animal horns and hooves.

    483. Maximum harm to a tree is caused by

    (1) loss of half of its leaves
    (2) loss of all leaves
    (3) loss of half of its branches
    (4) loss of its bark
    483. (2) Loss of all leaves lead to maximum harm as the tree loses its ability to perform photosynthesis so necessary for food manufacturing. Besides, loss of its bark will also be dangerous as it is the only part of a tree that is really alive. There is thin layer of cells right under the bark. If the bark is gone that
    layer dries out and dies.

    484. Vitamin E is particularly important for

    (1) development of teeth
    (2) carbohydrate metabolism
    (3) normal activity of sex glands
    (4) general health of epithelial tissues
    484. (3) Vitamin E is a powerful antioxidant that helps improve circulation. Apart from sexual desire itself, circulation is the most important component of sexual function. Good bodily circulation is mandatory for a good sex life. A deficiency in vitamin E can cause anemia, or a low red blood cell count, which affects your body's ability to produce sex hormones that promote reproductive system function.

    485. Birds usually have a single

    (1) Kidney 
    (2) Lung
    (3) Testis 
    (4) Ovary
    485. (4) Female birds in most families have only one functional ovary (the left one), connected to an oviduct — although two ovaries are present in the embryonic stage of each female bird.

    486. Alfalfa is the name of a kind of

    (1) Forest 
    (2) Crop
    (3) Grass 
    (4) None of these
    486. (2) Alfalfa is a small seeded crop, and has a slowlygrowing seedling, but after several months of
    establishment, forms a tough 'crown' at the top of the root system. This crown contains many shoot
    buds that enables alfalfa to re-grow many times after being grazed or harvested. Alfalfa is widely grown
    throughout the world as forage for cattle.

    487. Which cells in our body have the least regenerative power?

    (1) Brain cells
    (2) Mussle cells
    (3) Bone cells
    (4) Liver cells
    487. (1) Brain cells do not regenerate. Once lost, they do not come back. Research from Karolinska Institute in Sweden haves shown that the nerve cells of the brain remain the same throughout a person's life.

    488. Which one of the following pairs is correctly matched ?

    (1) Tetanus BCG
    (2) Tuberculosis - ATS
    (3) Malaria - Chloroquin
    (4) Scurvy - Thiamine
    488. (3) Chloroquine prevents the development of malaria parasites in the blood. Doctors use it to both prevent and treat malaria. After the malaria parasite Plasmodium falciparum started to develop widespread resistance to chloroquine, new potential uses of this cheap and widely available drug have been investigated.

    489. The carbon dioxide content in the air that we exhale is about

    (1) 4% 
    (2) 8%
    (3) 12% 
    (4) 16%
    489. (1) The air we breathe in contains about 0.04% carbon dioxide. The air we breathe out contains about 4% carbon dioxide. In other words, exhaled air contains about 100 times the concentration of carbon dioxide that inhaled air does.

    490. Blood pressure is controlled by

    (1) Adrenal gland
    (2) Thyroid gland
    (3) Thymus
    (4) Corpus luteum
    490. (1) Adrenaline directly affects, regulates and determines the body's ability to maintain a healthy
    blood pressure. When the adrenal gland becomes damaged or contains tumors, an excess of adrenaline
    greatly increases blood pressure levels, causing severe headaches, weight loss and other serious problems.

    491. The total number of ear bones is

    (1) 2 
    (2) 4
    (3) 6 
    (4) 8
    491. (3) There are three bones in each human ear. The small ear bones are arranged in series, and are known as ossicles. Ear bones are the malleus, or hammer, the incus, or anvil, and the stapes, or stirrup. Together they form a short chain that crosses the middle ear and transmits vibrations caused by sound waves from the eardrum membrane to the liquid of the inner ear.

    492. Which one of the following is the most sensitive Indicator of the health of a community?

    (1) Birth rate
    (2) Infant mortality rate
    (3) Death rate
    (4) Maternal mortality rate
    492. (2) Infant Mortality Rate (IMR) s most widely accepted as one of the most sensitive indicator of health status of a country/region due to several reasons. The IMR always reflect the overall health scenario of a region/ country. The rate is low in developed countries and high to very high in developing underdeveloped countries. If health infrastructure (preventive and curative infrastructures) of a region of a country is very good, the IMR is always good.

    493. Bakeries use yeast in breadmaking because it

    (1) makes the bread hard
    (2) makes the bread soft and spongy
    (3) enhances the food values
    (4) keeps the bread fresh
    493. (2) Bread is usually made from wheat-flour dough that is cultured with yeast, allowed to rise, and finally baked in an oven. The fermentation due to yeast makes the bread soft and spongy.

    494. “Pace-maker” is associated with

    (1) Kidney 
    (2) Brain
    (3) Heart 
    (4) Lung
    494. (3) A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to initiate and regulate the beating of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate.

    495. It causes clotting of blood

    (1) Thrombin
    (2) Haemoglobin
    (3) Pectin
    (4) All of the above
    495. (1) There are two major facets of the clotting mechanism – the platelets, and the thrombin system.
    The thrombin system consists of several blood proteins that, when bleeding occurs, become activated. The activated clotting proteins engage in a cascade of chemical reactions that finally produce a substance called fibrin. Red blood cells become caught up in the web, and a “red clot” forms.

    496. The largest flightless bird which can run at a great speed is

    (1) Penguin 
    (2) Kiwi
    (3) Ostrich 
    (4) Emu
    496. (3) The Ostrich is the largest living species of bird. They usually weigh from 63 to 145 kilograms. Although it cannot fly, the ostrich is also the fastest-running bird today; it can run up to about 70 kilometres in an hour.

    497. Human beings have two ears because two ears help

    (1) to judge the direction of sound
    (2) to hear even a feeble sound
    (3) to enjoy music better
    (4) to distinguish between two kinds of sounds arriving at the ears in opposite directions
    497. (4) We have two ears basically to widen the scope of hearing so that we can find out where sounds are coming from, and from what distance; i.e., sound localization. The brain utilizes subtle differences in intensity, spectral, and timing cues to allow us to localize sound sources.

    498. The vitamin which cannot be had from any vegetables is

    (1) Vitamin B 
    (2) Vitamin C
    (3) Vitamin D 
    (4) Vitamin E
    498. (3) In humans, vitamin D is unique because the body can synthesize it (from cholesterol) when sun exposure is adequate (hence its nickname, the "sunshine vitamin").Very few foods in nature contain vitamin D. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are among the best sources.

    499. Which of the following is not a gland ?

    (1) Thyroid 
    (2) Stomach
    (3) Liver
    (4) Pancreas
    499. (2) The stomach is a muscular, hollow, dilated part of the digestion system which functions as an important organ of the digestive tract in some animals, including vertebrates. It secretes protein-digesting enzymes called protease and strong acids to aid in food digestion.

    500. A person having blood type B could safely donate blood to persons with blood types

    (1) A and O 
    (2) B and O
    (3) A and AB 
    (4) B and AB
    500. (4) If someone belongs to the blood group B, he has B antigens on the surface of his red blood cells and A antibodies in his blood plasma. So he can donate blood to persons of B and AB blood groups, but cannot receive blood from persons having B or O groups

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