12-Bio-Botany-Unit-III Cell Biology And Genetics

Approved & Edited by ProProfs Editorial Team

The editorial team at ProProfs Quizzes consists of a select group of subject experts, trivia writers, and quiz masters who have authored over 10,000 quizzes taken by more than 100 million users. This team includes our in-house seasoned quiz moderators and subject matter experts. Our editorial experts, spread across the world, are rigorously trained using our comprehensive guidelines to ensure that you receive the highest quality quizzes.

Learn about Our Editorial Process

| By Padasalai12bot

Padasalai12bot

Community Contributor

Quizzes Created: 6 | Total Attempts: 10,793

Questions: 13 | Attempts: 2,519 | Updated: Mar 21, 2023

Questions

Settings

Feedback

During the Quiz End of Quiz

Difficulty

Sequential Easy First Hard First

Play as

Quiz Flashcard

Create your own Quiz

Share on Facebook Share on Twitter Share on Whatsapp Share on Pinterest Share on Email Copy to Clipboard Embed on your website

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
Correct Answer
A. Waldeyer

Explanation
The term "chromosome" was introduced by Waldeyer.

Rate this question:
2.

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

Explanation
Bridges is the correct answer because he was the first to provide experimental evidence that genes are carried by the chromosome.

Rate this question:
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
Correct Answer
A. 7:1:1:7

Explanation
The given answer, 7:1:1:7, represents a coupling test cross ratio. This ratio indicates the relative frequencies of different genotypes in a test cross between two heterozygous individuals. The presence of the same alleles on opposite chromosomes (7:7) suggests that these alleles are tightly linked and likely to be inherited together. The presence of a different allele (1) in the middle suggests recombination has occurred. This ratio suggests that recombination is less likely to happen between the outer alleles (7) and more likely to occur between the middle allele (1) and the outer alleles.

Rate this question:
4.

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

Explanation
During the pachytene stage of prophase I of meiosis, recombination of chromosomes occurs. This is when homologous chromosomes pair up and exchange genetic material through a process called crossing over. This exchange of genetic material leads to genetic diversity in offspring. Therefore, pachytene is the correct stage for recombination to take place.

Rate this question:

1
0
5.

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

Explanation
Hugo de Vries first used the term mutation based on his observation on Oenothera lamarckiana.

Rate this question:
6.

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

Explanation
Neurospora is a genus of fungi that is commonly used in genetic research. Biochemical mutants of Neurospora have been extensively studied and it has been observed that these mutants are unable to synthesize certain amino acids. This suggests that Neurospora plays a crucial role in the biosynthesis of amino acids.

Rate this question:
7.

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

Explanation
Nullisomy is a type of aneuploidy where there is a loss of both homologous chromosomes of a pair, resulting in a total chromosome number that is two less than the diploid number (2n). Therefore, the correct answer is 2n - 2.

Rate this question:
8.

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

Explanation
Drosophila melanogaster, commonly known as fruit flies, have four chromosomes in their gametes. Chromosomes are the structures that contain the genetic material of an organism. In fruit flies, there are four distinct chromosomes that carry the genes responsible for various traits and characteristics. These chromosomes are passed on to the offspring through the gametes, which are the reproductive cells. Therefore, the correct answer is four chromosomes.

Rate this question:
9.

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

Explanation
Watson and Crick proposed the double helix DNA model. They are known for their discovery of the structure of DNA, which they published in 1953. Their model explained how DNA is composed of two strands that are twisted together in a helical shape, forming a double helix structure. This model revolutionized our understanding of genetics and laid the foundation for further research in the field.

Rate this question:
10.

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

Explanation
The width of a DNA molecule is 20 Å. This measurement refers to the distance between the two strands of the DNA double helix. The width of DNA is important because it determines the spacing between the nucleotide bases, which in turn affects the overall structure and stability of the molecule. The correct answer is 20 Å.

Rate this question:
11.

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

Explanation
RNA is universally present in all organisms except in DNA viruses. This is because DNA viruses replicate their genetic material using a DNA-dependent DNA polymerase, which means they do not require RNA for replication. In contrast, all other organisms, including bacteria, algae, and TMV (Tobacco mosaic virus), use RNA in various cellular processes such as protein synthesis and gene regulation.

Rate this question:
12.

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

Explanation
mRNA, or messenger RNA, is a type of RNA molecule that carries genetic information from the DNA to the ribosomes, where it is used as a template for protein synthesis. It is a relatively small portion of the total RNA content in the cell. Therefore, the correct answer is 3 - 5%, indicating that mRNA makes up only a small fraction of the RNA content in the cell.

Rate this question:
13.

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

Explanation
In bacterial cells, there are more than 70 tRNAs. These tRNAs are responsible for carrying specific amino acids to the ribosomes during protein synthesis. Each tRNA molecule has a specific anticodon sequence that matches with a specific codon on the mRNA. This allows the tRNA to bring the correct amino acid to the growing polypeptide chain. The large number of tRNAs in bacterial cells ensures that there is a wide range of amino acids available for protein synthesis, allowing for the production of diverse proteins necessary for the cell's functioning.

Rate this question:

Quiz Review Timeline +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

Current Version
Mar 21, 2023

Quiz Edited by
ProProfs Editorial Team
Dec 01, 2013

Quiz Created by
Padasalai12bot

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

The term chromosome was introduced by

Who had first proved that the genes are carried by the chromosome?

The coupling test cross ratio is

Recombination of chromosome takes place in _____ stage of prophase I of meiosis.

Hugo de Vries first used the term mutation based on his observation on

Biochemical mutants of _____ failed to synthesize certain amino acids.

Nullisomy is represented by

The gametes of Drosophila melanogaster carry

Double helix DNA model was proposed by _____

The width of DNA molecule is

RNA is universally present in all organisms except in _____

MRNA is about _____ of the RNA content of the cell

In bacterial cell, there are more than _____ tRNAs