Biology

Cell Cycle and Chromosomes

1,219 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 the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

Chromosome end is called

  1. Telomere

  2. Centromere

  3. Satellite

  4. Metamere
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • A telomere is the end portion of a chromosome.
  • It is a region of repetitive nucleotide sequences present at each end of a chromosome that helps the chromosome from deterioration or fusion with other chromosomes. 
  • So, the correct answer is 'Telomere'.
Multiple choice botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

Read the given statements
(i) Centromere is present in the middle of the chromosome and forms two equal arms.
(ii) Chromosome has a terminal centromere
(iii) Centromere lies close to the end of the chromosome forming one extremely short and one very long arm
(iv) Centremere lies slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm.
Select the correct option as per the codes given above-

  1. Meta centric- (i); Submeta centric- (iv); Acro centric- (iii); Telo centric- (ii)

  2. Meta centric- (i); Submeta centric- (ii); Acro centric- (iii); Telo centric- (iv)

  3. Meta centric- (iv); Submeta centric- (iv; Acro centric- (iii); Telo centric- (ii)

  4. Meta centric- (iv); Submeta centric- (ii); Acro centric- (iii); Telo centric- (i)
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Every chromosome has a primary constriction or the centromere on the sides of which kinetochores are present. Based on the position of centromere, the chromosomes are of 4 types:

  • Metacentric -  Centromere is present in the middle of the chromosome and forms two equal arms.
  • Submetacentric -  Centromere lies slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm.
  • Acrocentric - Centromere lies close to the end of the chromosome forming one extremely short and one very long arm. 
  • Telocentric - Chromosome has a terminal centromere. 
  • So, the correct option is 'Option A' .

Multiple choice botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

When stained with a certain dye, the chromosomes show alternate light and dark bands known as Q-bands under the microscope. Name the dye.

  1. Fluorescent dyes

  2. Haematoxylin

  3. Giemsa stain

  4. Quinacrine mustard
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Q band is a typical pattern which is obtained by using Quinacrine mustard dye. Nucleus located in the centre of each cell has chromosomes coiled in the form of chromatin network. Chromosomes are gene carriers. They are made up of 2 chromatids, that are joined to each other through a centromere. 

heterochromatic DNA which is firmly packed and coiled is commonly stained by this dye. The pattern is similar to that obtained by light and dark bands obtained by G banding. The regions having rich Adenine Thymine complexes are highlighted with yellow fluorescence as seen in Q banding.
So the correct answer is " Quinacrine mustard ".

Multiple choice bio-chemistry unit of living - cell eukaryotic cell kinds of cell introduction to eukaryotic cell

Which of the following represents the correct sequence of relative sizes in descending order?

  1. Cell, nucleus, chromosome, water molecule, oxygen atom

  2. Cell, nucleus, water molecule, oxygen atom, chromosome

  3. Chromosome, cell, nucleus, water molecule, oxygen atom

  4. Cell, nucleus, water molecule, chromosome, oxygen atom
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cells are the largest units listed, followed by the nucleus within the cell, then chromosomes within the nucleus, followed by molecules, and finally atoms.

Multiple choice biology life processes in living organism movements in plants coordination in plants tropic and nastic movements in plants

Centromere is a part of chromosome which helps in the 

  1. Division of centrosomes

  2. Formation of spindle fibres

  3. Movement of chromosomes

  4. Formation of nuclear spindle
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Centromere joins the microtubules of 'Chromosomal spindle fibres and helps in the movement of chromosome during cell division. Centromere also plays an important role in the polymerization of tubulin protein used in the formation of microtubules. Hence it is helpful in attaching the chromosome with spindle fibres.

Multiple choice biology chemical coordination in plants cytokinins plant hormones plants and animal hormones

Cytokinesis refers to ................

  1. Division of chromosomes

  2. Division of cytoplasm

  3. Division of nucleus

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cytokinin is a plant hormone which is vital for the mitotic divisions taking place in plants. It thus enables cytokinesis and karyokinesis in the cells. This makes cytokinin an important constituent in callus culture.

Multiple choice classification of pteridophytes kingdom plantae plant kingdom biology

The cell of Dryopteris, prothallus contain nucleus with

  1. 4 n chromosomes

  2. 3 n chromosomes

  3. 2 n chromosomes

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

Prothallus is the self supporting haploid plant of the gametophytic generation and is concerned with sexual reproduction. Prothallus is generally monoecious and bears sex organs on the ventral side.

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

Cause of chromosome laggards in meiosis is?

  1. Inversion

  2. Dicentric chromosome

  3. Acentric chromosome

  4. Duplication of a gene
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A laggard is defined as a chromosome that does not overlap along the long axis of the spindle with any of the properly segregating chromosomes. A dicentric chromosome is an abnormal chromosome with two centromeres. It is formed through the fusion of two chromosome segments, each with a centromere, resulting in the loss of acentric fragments (lacking a centromere) and the formation of dicentric fragments.

So, the correct answer is 'Dicentric chromosome'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

What are the spindle fibres that connect the centromere of chromosome to the respective poles called?

  1. Astral rays

  2. Interpolar fibres

  3. Chromosomal fibres

  4. Inter chromosomal fibres
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The central region of the chromosome where the two arms of chromatid are attached is called as the centromere. It is the region where the spindle fibers attach at the time of the cell division and are called as chromosomal fibers. 
Thus the correct answer is option C. 
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Spindle chromosomes have

  1. Centriole

  2. Kinetochore

  3. Chromocentre

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

Chromosomes when attached to spindle fibres are called as spindle chromosomes. These Chromosomes have narrow very lightly coloured centromere or primary constriction. The centromere has a proteinaceous covering called as kinetochore on the two free surface of the centromere complex. The kinetochore has centromere binding proteins.

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

Centromere is required for -

  1. Movement of chromosomes towards poles

  2. Cytoplasmic cleavage

  3. Crossing over

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

Centromere is present in every cell. It is a specific DNA sequence in a chromosome. It is specifically useful in the process of cell division. During mitosis, the spindle fibres attach to the centromeres via kinetochore and all the chromosomes are arranged in an equatoral plane. After this, the chromosomes move towards their respective poles and cell division takes place.

So, option A is the correct answer.