Competitive Exams: Botany MCQs (Practice_Test 7 of 104)

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  1. Which one of the following compounds is NOT a member of the electron transport chain?
    1. Ubiquinone
    2. Cytochrome C
    3. Carnitine
    4. NAD
  2. In the study of enzymes, a sigmoid plot of substrate concentration [S] versus reaction velocity [V] may indicate
    1. Michaelis-Menten kinetics
    2. Cooperative binding
    3. Competitive inhibition
    4. Noncompetitive inhibition
  3. The site of enzyme modification by phosphrorylation is the amino acid called
    1. Tyrosine
    2. Cysteine
    3. Lysine
    4. Serine
  4. The smallest unit of DNA capable of coding for the synthesis of a polypeptide is the
    1. Operon
    2. Promoter
    3. Cistron
    4. Replicon
  5. Kerbs cycle
    1. Liberates a minor part of energy durin respiration
    2. is operative in photorespiration
    3. Reactions are independent of oxygen supply
    4. Is a like between carbohydrate and nitrogen metabolism
  6. Which one of the following is an example of a plant adapted to highly saline coastal conditions?
    1. Sonneratia acida
    2. Anaardium occidentale
    3. Taxus baccata
    4. Gnetum gemon
  7. The function of a repressor protein in an operon system is to prevent protein synthesis by binding to
    1. The ribosome
    2. The RNA polymerase, thus blocking transcription
    3. A specify region of the mRNA, preventing translation to protein
    4. A specific region of the operon, preventing transcription of structural genes
  8. Which one of the following statements is TRUE about eukaryotic cells?
    1. Cycloheximide blocks elongation during translation
    2. Formulated ERNA is necessary for initiation of translation
    3. A single mRNA specifies for more than one gene product
    4. Erythromycin inhibits elongation during translation
  9. Which one of the following is NOT correct in respect of all transfer RNAs?
    1. The 5-end is phosphorylated
    2. They are single chains
    3. The anticodon loop is identical
    4. The 3-end base sequence is CCA
  10. How many high-energy phosphate bond equivalents are utilized in the process of activation of amino acids for protein synthesis?
    1. Four
    2. Two
    3. One
    4. Three
  11. If the fertilized egg of a plant has 40 chromosomes, the number of chromosomes present in the pollen mother cell is
    1. 80
    2. 160
    3. 40
    4. 60
  12. Which one of the following is the correct sequence of procedures for site-specific somatic hybridization in plants?
    1. Procuring haploid cells from the parental species-isolation of protoplasts by removing the cellulose wall-protoplast fusion-regeneration of the fused cell
    2. Isolation of somatic cells-extraction of protoplasts-protoplast fusion-cutting of the fused cell
    3. Isolation of haploid and somatic cells extraction of their protoplasts-regeneration-fusion of cells
    4. Enzymatic isolation of haploid cells-isolation of protoplasts fusion of extracted protoplasts-regeneration of the fused cell
  13. Which one of the following pairs is correctly matched?
      • Nutation
      • Movement due to injury
      • Traumatotropism
      • Movement due to change in turgor pressure
      • Thigmotropism
      • Movement of tendrils due to contact
      • Seism nasty
      • Movement of stem tips of twining plants
  14. Biological significance of selfincompatibility in plant kingdom it to
    1. Promote vegetative growth
    2. Increase biomass
    3. Promote out breeding
    4. Check population
  15. The upper dormant seeds of cocklebur (Xanthium) germinate only under high oxygen levels. The oxygen is required for
    1. Degradation of inhibitors
    2. Synthesis of promoters
    3. Respiration
    4. Photorespiration