Competitive Exams: Botany MCQs (Practice-Test 59 of 104)

  1. The length of a DNA molecule consisting of 5000 nucleotide pairs will be

    1. 0.17μm

    2. 1.7μm

    3. 17μm

    4. 170μm

  2. There are 64 triplets in mRNA, but all the triplets do not code for amino acids. The total number of triplets that code for amino acids is

    1. 20

    2. 21

    3. 60

    4. 61

  3. A DNA molecule having A + G/C + T = 0.71 shows that the molecule is

    1. Linear

    2. Circular

    3. Single-stranded

    4. Double-stranded

  4. Match List I with List II and select the correct answer using the codes given below the lists:

    List-I List-II
    1. Dictyosomes

    2. Mitochondria

    3. Vacuoles

    4. Grana

    1. Storage

    2. Photosynthesis

    3. Transport

    4. Secretion

    5. Respiration

    • A
    • B
    • C
    • D
      • 4
      • 5
      • 1
      • 2
      • 3
      • 4
      • 2
      • 1
      • 4
      • 5
      • 3
      • 2
      • 4
      • 3
      • 1
      • 2
  5. Consider the following statements:

    1. Pairing of chromosomes that are genetically and structurally identical is known as homologous pairing.

    2. The nuclear envelope is perforated by nuclear pores that serve as pathways between the nucleoplasm and cytoplasm.

    3. Structurally, the endoplasmic reticulum is made up of a stack of flattened secures, vacuoles and number of small vesicles

    4. Sometimes, a number of ribosome's associate them-selves with a messenger RNA to form polysomes

    Of these statements

    1. 1 and 3 are correct

    2. 2 and 4 are correct

    3. 1 and 4 are correct

    4. 2 and 3 are correct

  6. The resolving power of an optical microscope is given by (? -wavelength, NA = numerical aperture)

    1. ?/NA

    2. ?/2NA

    3. 2NA/?

    4. ? x2NA

  7. Reductional division involves

    1. Separation of non-sister chromatics

    2. Reduction of chromosome number

    3. Separation of sister chromatics

    4. Crossing over

  8. The most widely used plasmid is

    1. pTi

    2. pBR322

    3. pRi

    4. pUC1

  9. Which of the following phenomena were discovered for the first time in maize?

    1. Bridge-breakage-fusion cycle

    2. Bridge-breakage-fusion cycle

    3. Pseudoallelism

    4. Gene conversion

      1. 1 and 2

      2. 1, 2 and 3

      3. 1, 2 and 4

      4. 3 and 4

  10. In a diploid plant with 2n = 14, all the chromosomes form a ring structure during meiotic prophase. The reason for this is

    1. Multiple deletions

    2. Gene mutations

    3. Duplications

    4. Multiple reciprocal translocations

  11. Of the four different phases of mitotic cell cycle, usually the phase with the shortest duration is the

    1. G1

    2. S

    3. G2

    4. M

  12. The genetic material in the virus f X 174 is

    1. Single-stranded RNA

    2. Double-stranded RNA

    3. Single-stranded DNA

    4. Double-stranded DNA

  13. When the heterozygote in a population have a reproductive advantage, one can predict that

    1. They will produce only heterozygous offspring

    2. The individuals that are homozygous recessive will take over

    3. Both homozygous dominant and homozygous recessive individuals will continue to appear in future generations

    4. Homozygous dominant and homozygous recessive individuals will be completely eliminated

  14. When one amino acid is replaced by another owing to a mutation, it is called

    1. Frame-shift mutations

    2. Point mutation

    3. Nonsense mutation

    4. Mis-sense mutation

  15. Genes for 7 pairs of characters studied by Mendel are such that

    1. They are situated on seven different chromosomes

    2. Some of them are chloroplast dna

    3. All of them are on the same chromosome

    4. Some of them are on the same chromosome but are not linked