Competitive Exams: Zoology MCQs (Practice-Test 55 of 112)

    • Assertion (A): Calciferol is antagon nin.
    • Reason (R): Calciferol is synergistic to parathormone.
    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 the correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The immediate administration of nitrite is a highly effective treatment for cyanide poisoning.
    • Reason (R): Nitrite converts ferrohaemoglobin to ferrihaemoglobin, which has also binds cyanide. Thus, ferrihaemoglobin competes with cytochrome oxide for cyanide.
    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 the correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The degeneration of tadpole tail occurs during metamorphosis.
    • Reason (R): This degeneration is brought about by hydrulytic enzymes.
    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 the correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Geological evidence indicates that free oxygen began accumulating in the atmosphere about two billion years ago.
    • Reason (R): The free oxygen in the atmosphere is produced by cyanobacteria like forms.
    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 the correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Thalassaemia is a dreaded disease of blood caused by structural variations in a or β globin chains.
    • Reason (R): Structural variations in a or β globin are due to amino acid replacements.
    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 the correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

  1. Bacterial resistance to antibiotics is a genetic trait that is carried in the bacterial cell in

    1. chromosome

    2. intron

    3. plasmid

    4. centromere

  2. The main-function of a plasma membrane is to

    1. prevent water from entering or leaving

    2. control what goes into and out of the cell

    3. act as a sieve, allowing only food to pass

    4. maintain intra-cellular environment

  3. Proteins that are used only outside the cell, are synthesised

    1. in the mitochondria

    2. on the rough endoplasmic reticulum

    3. on the smooth endoplasmic reticulum

    4. on free ribosomes

  4. Most of the membrane lipids are synthesised in the

    1. endoplasmic reticulum

    2. lysosomes

    3. golgi apparatus

    4. mitochondria

  5. Match List I with List II and select the correct answer

    List-I List-II
    1. Nuclear Membrane

    2. Lysosome

    3. Golgi apparatus

    4. Cell membrane

    1. Single layered membrane

    2. Cis and trans faces

    3. Double layered membrane

    4. Endocytosis and exocytosis

    5. Polysome

    • A
    • B
    • C
    • D
      • 3
      • 1
      • 2
      • 4
      • 3
      • 1
      • 4
      • 5
      • 1
      • 3
      • 2
      • 4
      • 1
      • 3
      • 4
      • 2
  6. A characteristic feature of meiosis is

    1. a single DNA replication and one division of cytoplasm

    2. a single DNA replication and three divisions of cytoplasm

    3. two DNA replication cycles and two divisions of cytoplasm

    4. a single DNA replication and two divisions of cytoplasm

  7. The ‘sliding filament model’ is related to

    1. interaction between thick and thin filaments during muscle contraction

    2. microtubule movements during anaphase separation of chromosomes

    3. ciliary motion generated by dynein molecules

    4. actin polymerisation during amoeboid locomotion

  8. The mitosis promoting factor (MPF), which propels an animal cell into division stage, has two essential sub units: One is catalytic and the other is regulatory. Which one of the following is the regulatory sub unit of MPF?

    1. Cyclin

    2. Cdk (Cycin dependent kinase)

    3. Proline

    4. Uniquitin

  9. Which one of the following groups of the histones is formed by the nucleosome?

    1. H2A, H1, H3 and H4

    2. H2A, H2B, H3 and H4

    3. H1, H2B, H3 and H4

    4. H1, H3, H4 and H5

  10. Which enzyme catalyzes the unwinding of DNA helix during replication?

    1. Primase

    2. Topoisomerase

    3. DNA polymerase

    4. Helicase