Competitive Exams: Zoology MCQs (Practice-Test 100 of 112)

    • Assertion (A): Parthenogenetically developed individual is haploid in nature.
    • Reason (R): It develops from an egg without fertilization.
    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 metamorphosis in Ascidian tadpole is considered retrogressive.
    • Reason (R): In the process of metamorphosis gill openings are lost.
    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): When a beneficial mutation takes place it will always appear with increasing frequency in the next generation.
    • Reason (R): Gene mutation is a chemical change in a single gene.
    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. Danielli and Davson proposed a model for arrangement of

    1. DNA and histones in chromatin

    2. RNA and proteins in ribosomes

    3. lipids and proteins in cell membrane

    4. enzymes and coenzymes in mitochondria

  2. Which one of the following aspects of image formation is affected by the wavelength of illumination in the optical microscope?

    1. Resolution

    2. Magnification

    3. Contrast

    4. Clarity

  3. The smallest measuring unit in Cytology is

    1. millimeter

    2. millirnicron

    3. angstrom

    4. electron

  4. Microvilli are specialized components of

    1. nuclear envelope

    2. endoplasmic reticulum

    3. intercellular cementing substance

    4. plasma membrance

  5. Which one of the following mechanisms is involved in muscle contraction?

    1. Induction of Ca2 + activated ATP ase

    2. Polarization of cell membrane

    3. Transfer of electrons to NADH by ferrodoxin

    4. Formation of cyclic AMP by adenyl cyclase

  6. Which one of the following organelles is rich in acid phoshatases?

    1. Lysosomes

    2. Golgi complex

    3. Rough endoplasmic reticulum

    4. Nucleolus

  7. The specific enzyme marker of the outer membrance of mitochondria is

    1. succinate dehydrogenase

    2. ATP synthetase

    3. monoamine oxidase

    4. malate dehydrogenase

  8. Epinephrine is secreted by the cells. Of

    1. anterior pituitary

    2. adrenal

    3. thyroid

    4. gonads

  9. One of the major events associated with amoeboid locomotion is

    1. actin polymerization

    2. activation of acetylcholinesterase

    3. chromosome condensation

    4. microfilament disruption

  10. Polysomes are many

    1. ribosomes attached to an individual messenger RNA

    2. nucleosomes forming the chromatin structure

    3. lysosomes fusing during phagocytosis

    4. centrosomes clustering during mitotic division

  11. An electrochemical proton gradient occurs membrances of

    1. golgi cisternae

    2. nuclear envelope

    3. mitochondria

    4. lysosomes

  12. In cytosol, stacks of curved cisternae with associated tubules and secretory vesicles are identified as

    1. centrioles

    2. golgi complex

    3. smooth endoplasmic reticulum

    4. endosomes