Tag: nucleus and chromosome

Questions Related to nucleus and chromosome

Chromosomes with equal arms are called as

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

  1. Metacentric

  2. Telocentric

  3. Acentric

  4. Polycentric

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Correct Option: A
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.

Spindle fibres are attached to chromosomes in the region of 

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

  1. Chromosome

  2. Kinetochore

  3. Centrosome

  4. Chromonema

Show answer
Correct Option: B
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.

Chromosomes having equal or almost equal arms are called

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

  1. Metacentric

  2. Acrocentric

  3. Polycentric

  4. Acentric

Show answer
Correct Option: A
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'.

Metachromosome with medial centromere and equal arms is

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

  1. Telocentric

  2. Acrocentric

  3. Metacentric

  4. Submetacentric

Show answer
Correct Option: C
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'.

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

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

  1. Acrocentric

  2. Metacentric

  3. Sub-metacentric

  4. Telocentric

Show answer
Correct Option: A
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'.

A chromosome carrying centromere at one end is

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

  1. Acrocentric

  2. Telocentric

  3. Metacentric

  4. Submetacentric

Show answer
Correct Option: B
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'.

      Shape of chromosomes is determined by position of

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

      1. Centrosome

      2. Centromere

      3. Telomere

      4. Micromere

      Show answer
      Correct Option: B
      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'.

      The chromosome which lacks a centromere is

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

      1. Acentric

      2. Acrocentric

      3. Metacentric

      4. Telocentric

      Show answer
      Correct Option: A
      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'.

      Shape of metacentric chromosome in anaphase is

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

      1. L-shaped

      2. V-shaped

      3. J-shaped

      4. I-shaped.

      Show answer
      Correct Option: B
      Explanation:
      • Metacentric chromosomes are X-shaped chromosomes and the centromere are present in the centre so that the two arms are equal.
      • During anaphase, these chromosomes appear V-shaped as the chromosomes split and the daughter chromatids move to the opposite poles of the cell.
      • So, the correct answer is 'V-shaped'.

      A chromosome having subterminal centromere is

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

      1. Acrocentric

      2. Submetacentric

      3. Telocentric

      4. Metacentric

      Show answer
      Correct Option: A
      Explanation:

      A. An acrocentric chromosome is a  chromosome in which the centromere is located near to one end of the chromosome. 

      B.  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. 
      C. 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.
      D. Metacentric chromosomes are X-shaped chromosomes and the centromere are present in the centre so that the two arms are equal.
      So, the correct answer is 'Acrocentric'.