Biology GK Questions Quiz-64

Biology GK Questions Quiz-64

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

    1261.Scurvey is caused by:

    (1) Vitamin ‘D’ 
    (2) Vitamin ‘A’
    (3) Vitamin ‘C’ 
    (4) Vitamin ‘B’
    Answer:
    1261.(3) Scurvy is a disease resulting from a deficiency of vitamin C (ascorbic acid). It is sometimes also referred to as Barlow's disease, named after Sir Thomas Barlow, a British physician who described it in 1883. Scurvy can be prevented by consuming enough vitamin C, either in the diet or as a supplement.

    1262.The most suitable soil for the production of cotton is :

    (1) Black lava soil
    (2) Alluvial soil
    (3) Loamy soil
    (4) Well drained soil
    Answer:
    1262.(1) Black soil is most suitable for the cultivation of cotton. The deep and medium black lava soil of the Deccan and Malwa plateaus is considered ideal, though it can be grown on alluvial and red soil as well. The black cotton soil is also known as regur.

    1263.Chromosome designation of Turner sydrome is :

    (1) 44A+XO 
    (2) 44A+XXX
    (3) 44A+XXY 
    (4) 44A+XYY
    Answer:
    1263.(1) Turner syndrome is a rare chromosomal disorder characterized by partial or complete loss (monosomy) of one of the X chromosomes that affects females. Individuals with Turner syndrome have only 45 chromosomes, including just a single X chromosome. This monosomic has a chromosome complement of 44 autosomes and one X chromosome (44+XO). The abnormal condition probably originates from exceptional egg or sperm with no X chromosome.

    1264.The five key indicators of global climate change of our planet are :

    (1) Antartic Sea ice, Oxygen, Rainfall, Drought and Sea level
    (2) Sea-level, Rising temperatures, Rainfall, Nitrogen and Arctic Sea ice
    (3) Arctic Sea ice, Carbon dioxide, Global Temperature, Sea level and Land ice.
    (4) None of these
    Answer:
    1264.(3) National Aeronautics and Space Administration (NASA) has developed a series of interactive maps and graphs to describe the global climate and how it has changed over time. They focus on 5 key climate indicators:
    l carbon dioxide concentration
    l global surface temperature
    l Arctic sea ice
    l land ice
    l sea level

    1265.Maximum oxygen is available from :

    (1) Deserts
    (2) Green forests
    (3) Grass lands
    (4) Phytoplanktons
    Answer:
    1265.(4) Most of Earth’s oxygen comes from tiny ocean plants – called phytoplankton – that live near the water’s surface and drift with the currents. Like all plants, they photosynthesize – that is, they use sunlight and carbon dioxide to make food. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earth’s atmosphere (National Geographic).

    1266.Which of the following is a form of sexual reproduction:

    (1) Fragmentation
    (2) Haemapheoditism
    (3) Budding
    (4) Fission
    Answer:
    1266.(2) Hermaphroditism is a form of sexual reproduction. Hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes. Hermaphroditic plants—most flowering plants, or angiosperms—are bisexual. Hermaphroditic animals—mostly invertebrates such as worms, moss animals, trematodes, snails, slugs, etc—are usually parasitic, permanently attached to another animal or plant.

    1267.Which of the following is true with reference to blood platelets?

    (1) They have prominent nuclei.
    (2) They are involved in phagocytosis
    (3) They have a pigment called haemoglobin
    (4) They are also called thrombocytes.
    Answer:
    1267.(4) Platelets, also called thrombocytes, are a component of blood whose function is to stop bleeding by clumping and clotting blood vessel injuries. Unlike red and white blood cells, platelets are not actually cells but rather small fragments of cells.

    1268.The basic unit of biosystematics is

    (1) Phenotype 
    (2) Ecotype
    (3) Florotype 
    (4) Genotype
    Answer:
    1268.(2) Ecotype is the basic unit of Biosystematics. It is adapted to a particular environment but capable of producing fully fertile hybrids with other ecotypes. The term Ecotype was proposed by Turesson. According to him Ecotype is “an ecological unit to cover the product arising as a result of genotypical response of an ecospecies to a particular habitat.”

    1269.Which endocrine gland is found in chest cavity?

    (1) Pineal gland
    (2) Thymus gland
    (3) Adrenal gland
    (4) Thyroid gland
    Answer:
    1269.(2) The endocrine glands are widely distributed throughout the body. The pituitary gland, pineal gland and hypothalamus are located in the skull. The thyroid and parathyroid glands are in the neck, and the thymus gland is in the thoracic (chest) cavity. The thymus gland is only active until puberty. It helps the body protect itself against autoimmunity.

    1270.An organism that transmits disease from one individual to another is called

    (1) Hybrid 
    (2) Fragment
    (3) Vector 
    (4) Clone
    Answer:
    1270.(3) An organism that transmits a disease agent from an infected to a non-infected animal or plant is known as vector. The major classes of vectors are:
    l Non-living vectors (food, water, soil, other materials)
    l Arthropod vectors (fleas, ticks, mosquitoes)
    l Vertebrate vectors (rats, mice, cats, dogs, birds)

    1271.Which part of the cinchona yields a drug?

    (1) Pericarp 
    (2) Bark
    (3) Endosperm
    (4) Leaf
    Answer:
    1271.(2) The bark of cinchona tree yields quinine, a white
    crystalline alkaloid having antipyretic (fever-reducing), anti-malarial, analgesic (painkilling), and antiinflammatory properties. Quinine was the first effective Western treatment for malaria caused by Plasmodium falciparum.

    1272.The part of brain which controls emotional reactions in our body is

    (1) Hypothalamus 
    (2) Cerebrum
    (3) Meninges 
    (4) Thalamus
    Answer:
    1272.(1) The brain’s limbic system controls emotional expression through the hypothalamus, which has control over the body’s emotional responses systems. The hypothalamus is responsible for regulating hunger, thirst, response to pain, levels of pleasure, sexual satisfaction, anger and aggressive behavior, etc. It also regulates pulse, blood pressure, breathing, and arousal in response to emotional circumstances.

    1273.To reduce tooth decay most toothpastes contain a

    (1) Bromide 
    (2) Fluoride
    (3) Iodide 
    (4) Chloride
    Answer:
    1273.(2) Fluoride in toothpastes prevent tooth decay from progressing and can even reverse, or stop, early tooth decay. It works by promoting a chemical reaction in tooth enamel that draws in replacement minerals including calcium. Fluoride incorporates itself into enamel weakened by acid attack, making the tooth more resistant to future acid attacks.

    1274.An example of hormone is

    (1) Cytosine 
    (2) Renin
    (3) Oxytocin 
    (4) Peprin
    Answer:
    1274.(3) Oxytocin is an hormone that is normally produced in the hypothalamus and stored in the posterior pituitary gland. It plays a role in social bonding, sexual reproduction in both sexes, and during and after childbirth. It is released due to stretching of the cervix and uterus during labor and with stimulation of the nipples from breastfeeding.

    1275.What is the famous ‘Chipko’ movement associated with?

    (1) Saving the tigers
    (2) Saving the wetland
    (3) None of these
    (4) Trees
    Answer:
    1275.(4) The Chipko movement refers to an organized resistance to the destruction of forests that arose in India during the 1970s. The name of the movement comes from the word ‘embrace’, as the villagers
    hugged the trees, and prevented the contractors’ from felling them. In 1987, the Chipko Movement was
    awarded the Right Livelihood Award.

    1276.Which is the sensory receptor involved in detecting blood pressure?

    (1) Chemo receptor
    (2) Mechano receptor
    (3) Photo receptor
    (4) Magneto receptor
    Answer:
    1276.(2) Baroreceptors are sensors located in the blood vessels of all vertebrate animals that sense the blood pressure and relay the information to the brain, so that a proper blood pressure can be maintained. They are a type of mechanoreceptor sensory neuron that is excited by stretch of the blood vessel. Mechanoreceptors are the sensory receptors that respond to any type of primary stimuli of pressure.

    1277.Which one of the following is commonly known as ‘Pond Silk’?

    (1) Spirogyra 
    (2) Rhizopus
    (3) Yeast 
    (4) Ulothrix
    Answer:
    1277.(1) Pond silk is the common name of Spirogyra (algae) because it is very slimy in shape. It is also
    known as pond silk, water silk, pond scum or mermaid's trees because of its bright green silky  appearance. Its filaments shine like silk due to the presence of mucilage.

    1278.‘Gynecomastia’ is

    (1) Development of hair on ears in males
    (2) Increased height in females
    (3) Development of an extra finger in females
    (4) Development of breasts in males
    Answer:
    1278.(4) Gynecomastia is swelling of the breast tissue in boys or men, caused by an imbalance of the hormones estrogen and testosterone.The development of gynecomastia is usually associated with benign pubertal change. Disturbances in the endocrine system that lead to an increase in the ratio of estrogens/androgens are thought to be responsible for the development of gynecomastia.

    1279.The highest concentration of urea is found in

    (1) Hepatic portal vein
    (2) Dorsal aorta
    (3) Hepatic vein
    (4) Renal vein
    Answer:
    1279.(3) The liver produces urea and other waste materials and then it pours it all in the right ventricle of the heart for oxygenation. The heart then distributes the blood to various parts of the body. So the
    impure blood brought by the Hepatic Vein and other blood vessels gets distributed through the aorta.
    This clearly indicates that hepatic vein carries the largest amount of urea, while the renal vein carries
    the least.

    1280.Compounds that are needed for enzymes to function properly are

    (1) Steroids
    (2) Vitamins
    (3) Heavy metals
    (4) Buffers
    Answer:
    1280.(2) Vitamins are organic molecules that function in a wide variety of capacities within the body. The most prominent function of the vitamins is to serve as cofactors (co-enzymes) for enzymatic reactions. If an enzyme lacks the essential vitamin, it cannot perform its catalyst function properly.

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