Competitive Exams: Botany MCQs (Practice-Test 68 of 104)

  1. Which one of the following is a terminator codon?

    1. AUG

    2. UGA

    3. UUU

    4. UGG

  2. Match List I (Enzyme) with List II (Function) and select the correct answer using the codes given below the lists:

    List-I List-II
    1. DNA Ligase

    2. DNA polymerase

    3. DNase I

    4. DNA topoisomerase

    1. Catalyses the covalent union of segments of an interrupted sugarphosphate strand in double-stranded DNA

    2. End nuclease that digests either singlestranded or double-stranded DNA

    3. Produces single or-double-stranded breaks in DNA during replication to release tension brought about by the separation of double-strands

    4. Catalyses the formation of DNA worn deoxyribonucleotides using one strand bf DNA as template

    • A
    • B
    • C
    • D
      • 1
      • 4
      • 3
      • 2
      • 4
      • 1
      • 2
      • 3
      • 1
      • 4
      • 2
      • 3
      • 4
      • 1
      • 3
      • 2
  3. When the dominant alleles (or wild type) say AB are present on one chromosome and its alternative recessive allele (ab) are located on the other homologous chromosome AB/ab, then the linkage is said to be in

    1. Repulsion phase

    2. Coupling phase

    3. Neutral phase

    4. Dominant phase

  4. Sex determination by environmental factors is commonly observed in

    1. Drosophila melanogaster

    2. Melandrium album

    3. Mirabilis jalapa

    4. Bonellia viridis

  5. The absence of Y chromosome in human beings causes

    1. Turner's syndrome

    2. Klinefelter's syndrome

    3. Down's syndrome

    4. No abnormality

  6. Directional change in the gene frequency in a panmictic population is due to

    1. Genetic load

    2. Genetic code

    3. Genetic disorders.

    4. Genetic drift

  7. Successful exploitation of heterocyst depends upon the

    1. Presence of he erotic effect in the hybrid

    2. Availability of male sterility

    3. Out crossing nature of the flower

    4. He erotic effect and availability

  8. Lamp brush chromosomes found in certain organisms are directly related to metamorphosis. Which one of the following statements in this regard i5 incorrect?

    1. These are very large chromosomes

    2. These are actively engaged in RNA and protein synthesis and accumulation

    3. Lamp brush loops recede and these become normal looking chromosomal parts looking chromosomal parts

    4. They are compactly packed and have very high DNA Content

  9. The patches of thin-walled parenchyma extending from pith to cortex and lying between the vascular bundles are called

    1. Resin canals

    2. Oil ducts

    3. Modularly rays

    4. Phloem

  10. In which one of the following groups of plants would one find vessels in all the plants?

    1. Selaginella. Marchantia, Cycas, Schizandra

    2. Selaginella, Gnetum. Mxngfera, Marsilea

    3. Gnetum, Pinus, Ficus, Polytrichum

    4. Magnolia, Lycopodium, Funaria

    Azadirachta

  11. Vessels are absent in which one of the following families of angiosperms?

    1. Ranunculaceae

    2. Wmteraceae

    3. Myrtaceae

    4. Casuarinaceae

  12. Cork cells are impervious to water because of the presence of

    1. Lignin

    2. Cutin

    3. Suberin

    4. Pectin

  13. C − 3, C − 4 and CAM plant species are found in

    1. Crassulaceae

    2. Cactaceae

    3. Euphorbiaceae

    4. Poaceae

  14. Which one of the following branches of botany explains the modern Systematic on the basis of variation and evolution?

    1. Biosystematics

    2. Plant taxonomy

    3. Plant systematic

    4. Chemosystematics

  15. The compound pollen grain, massula is characteristic of

    1. Papilionaceae

    2. Caesalpiniaceae

    3. Mimosaceae

    4. Proteaceac