Biology

Cell Cycle and Chromosomes

1,348 Questions

Explore a curated list of questions covering the cell cycle, mitosis, and meiosis. Topics include DNA replication, chromosomal structures, and genetic disorders. This material is essential for students preparing for biology and general science competitive exams.

Cell cycle eventsDNA replicationMeiosis processChromosomal structuresGenetic disorders

Cell Cycle and Chromosomes Questions

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Select the incorrect match : 

  1. Submetacentric - L-shaped chromosomes chromosomes

  2. Allosomes - Sex chromosomes

  3. Lampbrush - Diplotene bivalents chromosomes

  4. Polytene - Oocytes of chromosomes amphibians
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Polytene chromosomes are large chromosomes which have thousands of DNA strands. They provide a high level of function in certain tissues such as salivary glands of Drosophila.

Lampbrush chromosomes are a special form of chromosome found in the growing oocytes of most animals, except mammals. Lampbrush chromosomes of amphibians, birds and insects are described best of all. Chromosomes transform into the lampbrush form during the diplotene stage of meiotic prophase I. They are bivalent.
So, the correct option is 'Polytene - Oocytes of chromosomes amphibians'.

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Maximum arm ratio is found in

  1. Metacentric chromosome

  2. Acrocentric chromosome

  3. Telocentric chromosome

  4. Submetacentric chromosome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The chromosomes were named according to the position of the centromeres. This is expressed in the ratio “long arm to short arm”. Here the following terms are used: metacentric (arm ratio 1.0–1.7), submetacentric (ratio 1.7–3.0), subtelocentric (ratio 3.0–7.0), acrocentric (ratio more than 7.0), and telocentric (chromosome with only one arm).

So, the correct answer is option B.

Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

In which chromosome the centromere is located at the terminal end of the chromosome

  1. Acrocentric

  2. Sub meta centric

  3. Meta centric

  4. Telocentric
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • A telocentric chromosome, the centromere is located at the terminal end of the chromosome. 
  • A telocentric chromosome has therefore only one arm.
  • Telomeres may extend from both ends of the chromosome, their shape is similar to letter I during anaphase. 
  • Hence, In the chromosome in which the centromere is located at the terminal end of the chromosome is Telocentric.
  • So, the correct answer is 'Telocentric'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Select the incorrect match from the following

  1. Submatacentric chromosomes - L shaped chromosomes

  2. Allosomes - sex chromosomes

  3. Lampbrush - Diplotene bivalents

  4. Polytene chromosomes- oocytes of amphibians
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Metacentric Chromosomes
Metacentric chromosomes have the centromere in the center, such that both sections are of equal length. Human chromosome 1 and 3 are metacentric.

Submetacentric Chromosomes
Submetacentric chromosomes have the centromere slightly offset from the center leading to a slight asymmetry in the length of the two sections. Human chromosomes 4 through 12 are submetacentric.

Acrocentric Chromosomes
Acrocentric chromosomes have a centromere which is severely offset from the center leading to one very long and one very short section. Human chromosomes 13,15, 21, and 22 are acrocentric.

Telocentric Chromosomes
Telocentric chromosomes have the centromere at the very end of the chromosome. Humans do not possess telocentric chromosomes but they are found in other species such as mice.

So, the correct answer is 'Submetacentric chromosomes-L shaped chromosomes.'
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Which chromosome may be lost during cell division?

  1. Giant chromosome

  2. Acentric chromosome

  3. Polycentric chromosome

  4. Telocentric chromosome
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Acentric chromosome may lost during cell division as centromere is absent in them. During metaphase and anaphase spindle fibres are not attached with them and so they are not able to reach to the poles.

Multiple choice botany kingdom plantae introduction to pteridophytes cryptogams pteridophyta pteridophytes

If the root cell of a pteridophyte contains 10 chromosomes, then the chromosome number in indusium, sperm mother cell and spore mother cell are respectively.

  1. 10,5,10

  2. 10,5,5

  3. 10,10,10

  4. 5,10,10
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The root cell is diploid (2n=10). The indusium is part of the sporophyte (2n=10). The sperm mother cell is part of the gametophyte (n=5). The spore mother cell is part of the sporophyte (2n=10).

Multiple choice examples of bryophytes plant kingdom biology

In Funaria, 20 chromosomes are present in rhizoids, then the number of chromosome in calyptra, theca and foot will be

  1. 20, 40, 40 respectively

  2. 40, 20, 20 respectively

  3. 20, 40, 20 respectively

  4. 40, 10, 20 respectively
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Rhizoids are part of the gametophyte (n=20). The sporophyte structures (calyptra is gametophytic tissue, but theca and foot are sporophytic 2n) have different ploidy. However, in Funaria, the calyptra is haploid (n=20), while theca and foot are diploid (2n=40).

Multiple choice examples of bryophytes plant kingdom biology

In Funaria, rhizoid contains 10 chromosome, then number of chromosome in seta, leaf and calyptra are respectively

  1. 20, 10, 20

  2. 10, 20, 20

  3. 20, 20, 10

  4. 20, 10, 10
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In Funaria, rhizoid contains 10 chromosome, then number of chromosome in seta, leaf and calyptra are respectively 20, 10 and 10. The number of chromosomes in leaf and calyptra wil be the same as the rhizoid but the number of chromosomes in seta will be 2n that is double the number of chromosomes present in the rhizoids.

Multiple choice

How are diploid chromosomes represented?

  1. n

  2. 3n

  3. 2n

  4. 4n
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In genetics, 'n' represents the haploid number of chromosomes. Diploid cells, which contain two sets of chromosomes, are represented as '2n'.

Multiple choice

(TRUE or FALSE) On a karyogram, the sex of a child can be deduced from the 21st chromosomes.

  1. False, it can be deduced from the first pair of chromosomes.

  2. True, 21st set of chromosomes contains the XY chromosomes.

  3. False, sex can be determined by the X and Y chromosomes.

  4. True, since the 21st set of chromosomes is the last set.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a human karyogram, the sex of an individual is determined by the 23rd pair of chromosomes (the sex chromosomes, X and Y), not the 21st pair.

Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Datura is a classical example of study of

  1. Monosomics

  2. Trisomics

  3. Triploids

  4. Nullisomics
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Trisomics are those organisms, which have an extra chromosome (2n + 1). Trisomics were obtained for the first time in Datura stramonium (jimson weed) by A.F. Blakeslee and his co-workers. Since haploid chromosome number in this species is n = 12, 12 primary trisomics, 24 secondary trisomics and a large number of tertiary trisomics are possible. Most of the trisomics were identified by size, shape and other morphological features of the fruit.
So, the correct answer is 'Trisomics'.
Multiple choice biology pictorial feature of plant kingdom phanerogams gymnosperms angiosperms

Among angiosperm plants, the lowest chromosome & number is found in _________________.

  1. Haplopappus gracilis

  2. Crepis capillaris

  3. Arabidopsis thaliana

  4. Oenothera lamarckiana
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Haplopappus gracilis is well-known in botany for having one of the lowest chromosome numbers (2n = 4) among angiosperms.

Multiple choice

Which is true about binary fission?

  1. 2 cells line up

  2. chromosomal DNA is copied

  3. a bud pinches off

  4. the nucleus breaks down
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Binary fission is a form of asexual reproduction in prokaryotes. The process involves the replication of the circular chromosomal DNA followed by cell division.