Competitive Exams: Zoology MCQs (Practice-Test 73 of 112)

  1. Which one of the following body structures of an insect is an adaptation entirely meant for water conservation?

    1. Trache

    2. Invigilated spiracles

    3. Intimal lining

    4. Malphigian tubules

  2. Horse bot flies belonging to the family Gastrophilidae cause harm

    1. As an ectoparastic of livestock

    2. By feeding on the blood of livestock

    3. As an endoparasite of the livestock

    4. By transmitting disease pathogens

  3. Consider the following statements: The effects of biological control measures become pronounced because of

    1. Insecticidal sprays

    2. Quick rotation of crops

    3. Introduction of new varieties of crops

    4. Mechanical collection of insects

    Of these statements

    1. 1 alone is correct

    2. 1 and 2 are correct

    3. 2, 3 and 4 are correct

    4. 1, 3 and 4 are correct

  4. At which one of the following trophic levels is DDT sprayed to control insect pests of crops?

    1. Primary producers

    2. Primary consumers

    3. Secondary consumers

    4. Certiary consumers

  5. ‘Parasitic flies are often more important enemies of insects than are the Hymenoptera. Tachina fly has a large variety of caterpillar hosts and usually succeeds in keeping several of them under complete subjugation’ The above statement clearly establishes association between Tachina fly and caterpillars. Keeping in view the type of mouth parts available in the Order Diptera, the fly-caterpillar association is established through

    1. Ectoparasitism

    2. Endoparasitism

    3. Predation

    4. Oviposition

  6. The kissing bug Rhodnius is of considerable value as

    1. An experimental animal

    2. A rodent parasite

    3. It feeds on muscoid flies

    4. A pollinating agent

    • Assertion (A): One of the X chromosomes in female mammals appears as heterochromatin throughout the cell cycle. The process of X chromosome inactivation is often termed Lionization.
    • Reason (R): The inactivated heterochromatin allows for an even balance of X-linked genes between males and females.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): No transcription occurs within heterochromatin. Genes can be inactivated by chromosomal rearrangements that insert them into heterochromatic region.
    • Reason (R): Heterochromatin regions apparently remain condensed throughout the life cycle of the cell.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Dipnoi fishes show discontinuous distribution.
    • Reason (R): They are present only in the sea water.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Terrestrial insects excrete nitrogenous waste in the form of uric acid.
    • Reason (R): Excretion of uric acid requires the least amount of water.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): In Brachiostoma, the coelome is enterocoelic.
    • Reason (R): In Branchiostoma coelome is formed by the splitting of mesodermal sheet.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Knowledge derived from geology has led to the belief that on our planet there have been no deposits without traces of life.
    • Reason (R): The existence of life, wherever circumstances warrant its existence, is one of the characteristic features of the universe.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Parasitic organisms possess specialized body structures and a complex life history.
    • Reason (R): A parasite has to live in peculiarly specific surrounding and acutely face the problem of dispersal.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The only recognizable community boundary comprises the limits of the biosphere spreading all over the earth.
    • Reason (R): Communities do not have firm and definite boundaries either in space or time.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Insects are known to develop resistance to insecticides.
    • Reason (R): Natural selection is a phenomenon that is generally exhibited by organisms.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is NOT a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true