Competitive Exams: Botany MCQs (Practice-Test 99 of 104)

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

    List-I List-II
    1. Nucleolus

    2. Spherosomes

    3. Peroxisomes

    4. Plasmodesmata

    1. Lipid storage

    2. Glycolate metabolism

    3. Transport of macromolecules

    4. RNA-synthesis

    • A
    • B
    • C
    • D
      • 4
      • 1
      • 3
      • 2
      • 1
      • 2
      • 4
      • 3
      • 4
      • 1
      • 2
      • 3
      • 1
      • 3
      • 2
      • 4
  2. Mitotic cells cycle is divided typically into four phases, G1, S, G2 and M. Considering a mitotic cycle time of 18 hours, the distribution of period of time (in hours) for each of these phase will be. G1 S G2 M

    1. 1 3 5 9

    2. 9 1 3 5

    3. 9 5 3 1

    4. 3 5 9 1

  3. In a proliferating cell system, how many mitotic divisions are required to produce 1024 cells from a single parent cell?

    1. 10

    2. 20

    3. 512

    4. 1023

  4. In diploid systems, the genes located on the chromosome regions between the Centro mere and the first chiasm a (from the Centro mere), at meiosis-I, exhibit the type of phenomenon called

    1. Non-disjunction

    2. Pre-reduction

    3. Post-reduction

    4. Double reduction

  5. Mendel proposed his ‘laws’ on the basis of his researches on seven contrasting characters in garden pea which has 14 chromosomes per somatic cell. If, instead of garden pea, Mendel had chosen to work on seven characters in a plant species having only four chromosomes per somatic cell, then the most likely outcome would have been that

    1. He would have discovered blending inheritance

    2. He could not have proposed that genes are located on the chromosomes

    3. He might not have discovered the law of independent assortment.

    4. He might not have discovered the law of segregation

  6. In humans, red-green color blindness is recessive and sex-linked, while albinism is recessive and autonomic A marriage between two homozygous parents, a normal versioned albino woman. And a color-blind and normally pigmented man will produce children

    1. Who are all phenotypic ally normal versioned and have normal pigmentation

    2. Half of whom are color-blind and the other half having normal vision, and all of them having normal pigmentation

    3. All of whom have normal vision, but half of whom are albino and the other half with normal pigmentation

    4. Of four categories, normal versioned. Pigmented: Normal versioned, albino; color-blind, pigmented: Color-blind, albino: All in equal proportions

  7. A dithered tall plant bearing yellow flowers (Tt. Yy) was-crossed with a dwarf plant bearing white flowers (tt, yy). What percentage of the progeny is expected to be homozygous tall bearing yellow flowers?

    1. 75

    2. 50

    3. 25

    4. Zero

  8. A significant effect of ultraviolet radiation is the

    1. Production of base tautomers

    2. Breakage of phosphodiester bonds

    3. Formation of pyrimidine dimers

    4. Induction of autotrophic mutants

  9. Relative heterosis represents heterotic effect over the

    1. Mid-parental value

    2. Better parent

    3. Check parent

    4. General population mean

  10. A regulatory gene produces some kind of protein through its mRNA that controls the activity of the operator gene which signals the formation of specific enzymes required for the metabolic breakdown of the food. How does that protein regulate the activity of the operator gene?

    1. The repressor protein produced after combining with an inducer activates the operator gene

    2. The repressor protein produced after combining with a co repressor activates the operator gene

    3. The catabolic activator protein (CAP) produced activates the operator gene

    4. The mutated repressor protein produced activates the operator gene

  11. In the case of double-stranded DNA, which of the following base ratios are always equal to one?

    1. (A + T)/(G + C)

    2. (A + G)/(C + T)

    3. C/G

    4. (G + T)/(A + C)

    Select the correct answer

    1. 1 and 2

    2. 1 and 3

    3. 2, 3 and 4

    4. 1.3 and 4

  12. Genomes of prokaryotes consists mostly of

    1. Repetitive DNA sequences

    2. Unique DNA sequences

    3. Interspersed DNA sequences

    4. Clustered repeated DNA sequences

  13. Post-transcriptional processing of all varieties of eukaryotic RNA occurs

    1. In the nucleus

    2. In the cytoplasm

    3. In the nucleus for some RNA and in the cytoplasm for other RNAs

    4. Before the RNA transcript separates from its complementary site on DNA

  14. Give a chromosome segment a-b-c With 40% interference, the frequency of double cross-over (dco) will be

    1. 20%

    2. 10%

    3. 1.2%

    4. 0.12%

  15. In tomato, three pairs of genes are located on a chromosome. Of these two are linked. There is 8% recombination between the genes for tallness (T) and smooth surface (S), There is 20% recombination between tallness and oval shape (O) of the fruit, and 12% between oval shape fruit and smooth fruit surface. The correct sequence of the genes is

    1. S O T

    2. S T O

    3. T S O

    4. O T S