12-bio-botany-unit-III Cell Biology And Genetics

13 Questions | By Padasalai12bot | Updated: Mar 21, 2022 | Attempts: 2492

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Prepared by Mr. D. Rajamani, M. Sc. ,M. Ed. , P. G. Asst Botany A. C. S Mat. Hr Sec. School, Arni. Tiruvannamalai Dist & www. Padasalai. Net

Questions and Answers

1.

The term chromosome was introduced by
- A.
  
  Waldeyer
- B.
  
  Bridges
- C.
  
  Balbiani
- D.
  
  Flemming
2.

Who had first proved that the genes are carried by the chromosome?
- A.
  
  Bridges
- B.
  
  Waldeyer
- C.
  
  Balbiani
- D.
  
  Flemming
3.

The coupling test cross ratio is
- A.
  
  7:1:1:7
- B.
  
  1:7:7:1
- C.
  
  1:1:1:1
- D.
  
  9:3:3:1
4.

Recombination of chromosome takes place in _____ stage of prophase I of meiosis.
- A.
  
  Pachytene
- B.
  
  Leptotene
- C.
  
  Zygotene
- D.
  
  Diplotene
5.

Hugo de Vries first used the term mutation based on his observation on
- A.
  
  Oenothera lamarckiana
- B.
  
  Sorghum
- C.
  
  Neurospora
- D.
  
  Cicer gigas
6.

Biochemical mutants of _____ failed to synthesize certain amino acids.
- A.
  
  Neurospora
- B.
  
  Sorghum
- C.
  
  Cicer arietinum
- D.
  
  Cicer gigas
7.

Nullisomy is represented by
- A.
  
  2n – 2
- B.
  
  2n – 1
- C.
  
  2n + 1
- D.
  
  2n + 2
8.

The gametes of Drosophila melanogaster carry
- A.
  
  Four chromosomes
- B.
  
  Three chromosomes
- C.
  
  Seven chromosomes
- D.
  
  Eight chromosomes
9.

Double helix DNA model was proposed by _____
- A.
  
  Watson and Crick
- B.
  
  O.T. Avery et al
- C.
  
  Griffith
- D.
  
  Stinberg
10.

The width of DNA molecule is
- A.
  
  20 Å
- B.
  
  18 Å
- C.
  
  34 Å
- D.
  
  35 Å
11.

RNA is universally present in all organisms except in _____
- A.
  
  DNA viruses
- B.
  
  TMV
- C.
  
  Bacteria
- D.
  
  Algae
12.

MRNA is about _____ of the RNA content of the cell
- A.
  
  3 - 5%
- B.
  
  10 - 20%
- C.
  
  5 - 10%
- D.
  
  20 - 30%
13.

In bacterial cell, there are more than _____ tRNAs
- A.
  
  70
- B.
  
  200
- C.
  
  300
- D.
  
  400