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

Kinetochore is the

  1. Fibrous granular structure within centromere.

  2. Protein disc near centromere

  3. Construction near chromosome end.

  4. End of chromosome.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The kinetochore is a disc-shaped protein complex associated with the centromere of a chromosome during cell division, to which the microtubules of the spindle attach.
  • It forms on a chromatid during cell division.
  • Hence Kinetochore is the protein disc near the centromere.
  • So, the correct answer is 'Protein disc near centromere'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Which chromosome may 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 chromosomes may be lost during cell division. An acentric fragment is a segment of a chromosome that lacks a centromere. Because the centromere is the point of attachment for the mitotic apparatus, acentric fragments are not evenly distributed to the daughter cells in cell division. As a result, one of the daughters will lack the acentric fragment. Lack of the acentric fragment in one of the daughter cells may have deleterious consequences, depending on the function of the DNA in this region of the chromosome

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

If the centromere is sub-median and the two arms are unequal then the chromosome is called as

  1. Metacentric

  2. Submetacentric

  3. Acrocentric

  4. Telocentric
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
The centromere is the part of a chromosome that links sister chromatids. During mitosis, spindle fibers attach to the centromere via the kinetochore. 
Having the centromere near the center but not in the middle, so that one arm is shorter than the other is the property of a submetacentric chromosome.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Which type of chromosome will appear 'L' -shaped during anaphase?

  1. Telocentric

  2. Acrocentric

  3. Metacentric

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

'L' shaped chromosomes that appear during anaphase are sub-metacentric. According to the position of the centromere, the metacentric chromosomes are X shaped and due to the unequal length of the arms of the chromosomes, they become L shaped and are called sub-metacentric.

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

Chromosome with centromere at one end is

  1. Metacentric

  2. Submetacentric

  3. Telocentric

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

Chromosome with centromere at one end is telocentric. A telocentric chromosome's centromere is located at the terminal end of the chromosome. Telomeres may extend from both ends of the chromosome. Humans do not possess telocentric chromosomes.

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

Small chromosomes which do not produce any detectable phenotypic expression are termed as

  1. Heterochromatic chromosomes

  2. Supernumerary chromosomes

  3. Nonsense chromosomes

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

A chromosome present in addition to the normal chromosome complement is called as a supernumerary chromosome, also known as accessory chromosome. These chromosome does not produce any detectable phenotypic expression in an organism. These chromosomes are not essential for the life of a species, and are lacking in some (usually most) of the individuals. Thus a population would consist of individuals with 0, 1, 2, 3 (etc.) supernumeraries.

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

A chromosome with centromere at one end is called as

  1. Telocentric

  2. Metacentric

  3. Apocentric

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

The rod-like chromosomes which have the centromere on the proximal end are known as the telocentric chromosomes. Humans do not possess telocentric chromosomes but they are found in other species such as mice. Thus, the correct answer is option A.

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

Chromosomes with equal arms are called as

  1. Metacentric

  2. Telocentric

  3. Acentric

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

A chromosome with the median centromere and two equal arms are called as metacentric chromosomes. The presence of centromere at the terminal end makes telocentric chromosome. Acentric chromosomes lack centromere and therefore have a single arm. The presence of centromere in diffused state makes the polycentric chromosomes as if they have multiple centromeres Thus, the correct answer is option A.

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

Spindle fibres are attached to chromosomes in the region of 

  1. Chromosome

  2. Kinetochore

  3. Centrosome

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

The kinetochore is a protein complex assembled at each centromere. It acts as an attachment site for spindle microtubules for chromosomal movement to the opposite poles. Thus the correct answer is option B.

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

Chromosomes having equal or almost equal arms are called

  1. Metacentric

  2. Acrocentric

  3. Polycentric

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

DNA is the way genetic information is stored within cells and allows the transmission of information from one generation to the next. There are four main types of chromosomes: metacentric, submetacentric, acrocentric, telocentric. Metacentric chromosomes are X-shaped, with the centromere in the middle so that the two arms of the chromosomes are almost equal. A chromosome is a metacentric if its two arms are equal or almost equal in length.
So, the correct answer is 'Metacentric'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

Metachromosome with medial centromere and equal arms is

  1. Telocentric

  2. Acrocentric

  3. Metacentric

  4. Submetacentric
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. A telocentric chromosome is a chromosome in which the centromere is located at the terminal end of the chromosome and their shape is similar to the letter i.
B. An acrocentric chromosome is a  chromosome in which the centromere is located near to one end of the chromosome. 
C. Metacentric chromosomes are X-shaped chromosomes and the centromere are present in the centre (medial) so that the two arms are equal.
D. A submetacentric chromosome is a chromosome in which the centromere is located near the slightly away from the centre and the two arms are slightly unequal in length and form L-shape. 
So, the correct answer is 'Metacentric'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

A chromosome, in which the centromere is situated close to its end so that one arm is very short and other very long is

  1. Acrocentric

  2. Metacentric

  3. Sub-metacentric

  4. Telocentric
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Every chromosome has a primary constriction of the centromere on the sides of which disc-shaped structures called kinetochores are present.
Based on the position of the centromere, the chromosomes can be classified into four types.
The metacentric chromosome has a middle centromere forming two equal arms of the chromosome.
The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm.
In the case of acrocentric chromosome the centromere is situated close to its end forming one extremely short and one very long arm.
Telocentric chromosome has a terminal centromere.
So, the correct option is 'Acrocentric'.
Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

A chromosome carrying centromere at one end is

  1. Acrocentric

  2. Telocentric

  3. Metacentric

  4. Submetacentric
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
    A. An acrocentric chromosome is a  chromosome in which the centromere is located near to one end of the chromosome. 
    B. A telocentric chromosome is a chromosome in which the centromere is located at the terminal end of the chromosome and their shape is similar to the letter i.
    C. Metacentric chromosomes are X-shaped chromosomes and the centromere are present in the centre so that the two arms are equal.

      D.  A submetacentric chromosome is a chromosome in which the centromere is located near the slightly away from the centre and the two arms are slightly unequal in length and form L-shape. 

      So, the correct answer is 'Telocentric'.

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

      Shape of chromosomes is determined by position of

      1. Centrosome

      2. Centromere

      3. Telomere

      4. Micromere
      Reveal answer Fill a bubble to check yourself
      B Correct answer
      Explanation
      • The shape of chromosomes is determined by the position of centromeres.
      • The centromere is the lighter staining region on the chromosome of a cell which appears as a constriction.
      • They are also known as a primary constriction or kinetochore.
      • It is a specialized DNA sequence that links a pair of sister chromatids where the spindle fibres are attached during cell division.
      • So, the correct answer is 'Centromere'.
      Multiple choice botany nucleus and chromosome membrane bound organelles cell: size and differentiation microscopy

      The chromosome which lacks a centromere is

      1. Acentric

      2. Acrocentric

      3. Metacentric

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

      A. Acentric chromosome lacks a centromere as the centromere is the point of attachment for the spindle fibres.

      B. An acrocentric chromosome is a  chromosome in which the centromere is located near to one end of the chromosome. 
      C. Metacentric chromosomes are X-shaped chromosomes and the centromere are present in the centre so that the two arms are equal.
      D. A telocentric chromosome is a chromosome in which the centromere is located at the terminal end of the chromosome and their shape is similar to the letter i or is rod-shaped.
      So, the correct answer is 'Acentric'.