Competitive Exams: Zoology MCQs (Practice-Test 68 of 112)

  1. Which one of the following is the largest chromosome?

    1. Supernumerary chromosome

    2. Polytene chromosome

    3. X chromosome

    4. Lampbruh chromosome

  2. Which of the following features characterise the puffs of the polytene chromosomes of Drosophila?

    1. Chromosomes are arranged side by side

    2. They are the sites of gene transcription

    3. They are inducible by ecdysone

    4. They are the regions of active protein syntehsis

    Codes:

    1. 1 and 2

    2. 2 and 3

    3. 3 and 4

    4. 1 and 4

  3. Certain genetic elements that regularly ‘jump’ to new locations, often inactivating the genes into which they become inserted, are called

    1. heterochromatin

    2. episomes

    3. overlapping genes

    4. transposons

  4. Based on current knowledge, which one of the following would represent the complete and accurate depiction of the ‘central dogma’ in Molecular Biology?

    1. DNA-RNA-Protein

    2. DNA-RNA-Protein

    3. DNA-RNA-Protein

    4. DNA-RNA-Protein

  5. Such partial duplicates of structural genes which have incorporated sufficient changes so that they are not biologically active and usually are not transcribed are called

    1. pseudoalleles

    2. multiple alleles

    3. pseudogenes

    4. constitutive heterochromatin

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

    List-I (character of man) List-II (Example)
    1. Sex-linked

    2. Sex-influenced

    3. Sex-limited

    1. Baldness

    2. Acquired Immuno deficiency syndrome

    3. Klinefeker's syndrome

    4. Haemophilia

    5. Tuft of hairs (hypertrichosis) on pinna

    • A
    • B
    • C
      • 4
      • 1
      • 5
      • 5
      • 3
      • 2
      • 5
      • 1
      • 3
      • 4
      • 3
      • 2
  7. What will be the phenotypic sex of the following organisms on the basis of the sex chromosomal constitution indicated against each organism? Organisms: Sex chromosomal constitution

    1. Human being: XO

    2. Drosophila: XO

    3. Human being: XXY

    4. Drosophila: XXY

    Select the correct answer using the following codes:

    Codes:

    Male: Female

    1. 1 and 3: 2 and 4

    2. 3 and 4: 1 and 2

    3. 2 and 4: 1 and 3

    4. 2 and 3: 1 and 4

  8. Point mutations area due to

    1. gross changes in chromosomes

    2. changes in the number of chromosomes

    3. changes in the nucleotide sequence of a gene

    4. changes in the normal arrangement of genes in the chromosome

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

    List-I List-II
    1. Incomplete dominance

    2. Codominance

    3. Polygenes

    4. Complementary genes

    1. Human skin colour

    2. Purple colour in maize due to anthocyanin

    3. Human being belonging to AB blood group

    4. Pink flower in 4 o'clock plant

    • A
    • B
    • C
    • D
      • 4
      • 3
      • 1
      • 2
      • 3
      • 4
      • 2
      • 1
      • 4
      • 3
      • 2
      • 1
      • 3
      • 4
      • 1
      • 2
  10. Kappa particles are the

    1. submicroscopic granules formed by the folding of the naked DNA

    2. endosymbionts representing the gram negative bacteria species

    3. viral particles capable of selfperpetuation in the host cytoplasm

    4. protozoan parasites whose multiplication is controlled by the host metabolites

  11. The first step in the biosynthesis of polypeptides is catalysed by

    1. initiation factors (IF)

    2. aminoacyl-tRNA synthetase

    3. peptidyl transferase

    4. terminal transferase

  12. After the addition of the last amino acid to a growing polypeptide chain during the process of protein synthesis one of the termination codons reaches the appropriate site on the ribosomal surface and then the following events take place:

    1. Release of tTNA molecule from the ribosome

    2. Dislodging of polypeptide chain from the IRNA

    3. Dissociotion of ribosomes into large and small subunites

    The correct sequence of these events is

    1. 1, 2, 3

    2. 3, 2, 1

    3. 2, 1, 3

    4. 3, 1, 2

  13. Chagas disease of Central and South America, in which the protozoan parasites multiply inside the muscles, the heart and the nervous system causing dangerous swellings, is caused by

    1. Entamoeba histolytica

    2. Trichomonas vaginalis

    3. Trypanosoma cruzi

    4. Giardia intestinalis

  14. Consider the following stages:

    1. Zygote

    2. Ookinete

    3. Oocyst

    4. Sporozoite

    In the life history of malarial parasite, the correct sequence of these stages in the mosquito host is

    1. 2, 1, 4, 3

    2. 1, 2, 4, 3

    3. 1, 2, 3, 4

    4. 2, 1, 3, 4

  15. More or less ring-shaped circular or horseshoe shaped coral reef partly or wholly enclosing a central lagoon is called

    1. barrier reef

    2. coral island

    3. fringing reef

    4. atoll