Competitive Exams: Botany MCQs (Practice-Test 48 of 104)

  1. Besides direct chemical analysis DNA and RNA can be detected by which of the following method?

    1. Photometric procedures

    2. Staining reactions

    3. Enzyme digestion

    Select the correct answer using the codes given below:

    Codes:

    1. 1, 2 and 3

    2. 1 and 2

    3. 2 and 3

    4. 1 and 3

  2. Under the concept of triplet code, the segment of DNA specifying one polyepticle chain is known as

    1. Transposon

    2. Operon

    3. Codon

    4. Cistron

  3. The double crossover types or combinations of two chromatics are furnished below. Which one of these gives no recombination?

    1. Four strand double crossover

    2. Two strand double crossover

    3. Three strand double crossover

    4. Another three strand double crossover

  4. Consider the following nucleic acids:

    1. DNA

    2. R-RNA

    3. T-RNA

    4. M-RNA

    The correct sequence of their participation in protein synthesis is

    1. I, II, III, IV

    2. II, III, IV, I

    3. III, II, I, IV

    4. I, IV, II, III

  5. The trihybrid phenotypic ration of 27: 9: 9: 9: 3: 3: 3: 1 is obtained because of

    1. Multiple alleles

    2. Interaction of genes

    3. Multiple factor inheritance

    4. Independent assortment of genes

  6. When a pea plant with yellow round seeds was crossed with a plant with green wrinkled seeds, yellow round, yellow wrinkled, green round and green wrinkled seed producing varieties were obtained in almost equal numbers. The genotypes of the patents in this cross are

    1. YYRR x yyrr

    2. YyRr x yyrr

    3. YYRr x yyrr

    4. YyRR x yyrr

  7. C-brands occur in chromosomal regions having

    1. Genes

    2. Pseudo alleles

    3. Heterochromatin

    4. Automation

  8. The cytoplasm-genetic male sterility and fertility restoration system using three lines, male sterile (A), maintainer (B) and restorer (R) is being used in many croplands for the production of hybrid seed. Identical nuclear genes are possessed by

    1. A and B lines

    2. A and R lines

    3. B and R lines

    4. A, B and R lines

  9. Multiple molecular forms of enzymes occurring within a plant system are known as

    1. Vitamins

    2. Co-enzymes

    3. Hormones

    4. Isohyets

  10. In a plant cell, DNA is present

    1. Only in chromosomes

    2. In chromosomes and chloroplasts

    3. In chromosomes, chloroplasts and mitochondria

    4. In chromosomes, chloroplasts mitochondria and ribosome's

  11. X-rays induce mutagenic changes mainly by

    1. Transitions

    2. Tran versions

    3. Frame-shifting

    4. Chromosomal breakage

  12. If, in Macrospore, the progenies of the cross between an Orange colonial strain and Albino spreading strain segregated into 1: 1: 1: 1 ratio of Albino spreading: Orange colonial: Normal Albino colonial, then the inference is that the traits are controlled by

    1. Single gene

    2. Two genes

    3. Three genes

    4. Four genes

  13. In the light of neo-Darwinism, which one of the following offers the greatest advantage to a population invading a new ecological niche?

    1. Outbreding

    2. Apomixes

    3. Vegetative propagation

    4. Inbreeding

  14. Transonic conditions is expressed as

    1. 2n − 1

    2. 2n + 2

    3. 2n + 1

    4. 2n − 2

  15. Diagrammatic representations of a chromosome is known as

    1. Homotype

    2. Idiotype

    3. Meroype

    4. Karyotype