Tag: the mitotic cell cycle

Questions Related to the mitotic cell cycle

Exceptionally, large chromosome is

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

  1. Lampbrush chromosome

  2. Polytene chromosome

  3. Megachromosomes

  4. All of the above

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Correct Option: D
Explanation:

All chromosomes mentioned are large chromosomes. These chromosomes are producing large amounts of RNA for the oocyte, and most of the genes present in the DNA loops are being actively expressed. Each lateral loop contains one or several transcription units with polarized RNP-matrix coating the DNA axis of the loop.The majority of the DNA, however, is not in loops but remains highly condensed in the chromomeres on the axis, where genes are generally not expressed. This is about lampbrush chromosomes, the polytene and mega chromosomes are also larger than the other normal chromosomes.

So, the correct answer is option D.

A thread like structure in the nucleus of a cell formed of DNA which carries the genes is

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

  1. DNA

  2. Genes

  3. Chromosomes

  4. Ribosomes

Show answer
Correct Option: C
Explanation:

Deoxyribonucleic acid (DNA) is the information-carrying molecule found in all living organisms. In most animal, plant and fungal cells, DNA is stored in the nucleus coiled up in thread-like structures called chromosomes.

So, the correct answer is option C.

Nucleus contains ________ which are rod shaped structures.

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

  1. Cytoplasm

  2. Chromosomes

  3. Chromatin

  4. Carbon particles

Show answer
Correct Option: B
Explanation:

Chromosomes are thread like structures located inside the nucleus of animal and plant cells. Each chromosome is made of deoxyribonucleic acid (DNA). Passed from parents to offspring, DNA contains the specific instructions that make each type of living creature unique.

Which chromosomes are called as supernumerary?

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

  1. B-chromosome

  2. Sex chromosome

  3. Double minutes chormosome

  4. Lampbrush chromosome

Show answer
Correct Option: A
Explanation:

B chromosomes are called supernumerary or accessory chromosomes. It is because these chromosomes are not considered as essential for being normal. These are not found in every individual. During alloploids, it suppresses homologous pairing which reduces multiple pairing between homologous chromosomes in allopolyploids.  

So, the correct option is A.

Who used the word "chromosome"

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

  1. Huxley

  2. Flemming 1888

  3. Kollikar 1888

  4. Waldeyer 1888

Show answer
Correct Option: D
Explanation:
Johannsen coined the term phenotype and genotype and conducted his pure line experiment in genetics.
Waldeyer 1888 used the term chromosome to describe certain structures that form during the process of cell division.
Benda coined the term mitochondria to describe their tendency to form long chains.
Flemming coined the term chromatin and mitosis, and also described the threadlike structure in the cell nucleus that was later named chromosome.
So, the correct option is 'Waldeyer 1888'.

Swellings present over the chromosomes are

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

  1. Centromeres

  2. Centrosome

  3. Puffs

  4. Chromomeres

Show answer
Correct Option: A
Explanation:
The centromere is the specialized DNA sequence of a chromosome that links a pair of sister chromatids
During mitosis, spindle fibers attach to the centromere via the kinetochore.
Centromeres were first thought to be genetic loci that directs the behavior of chromosomes
So, the correct answer is 'Centromeres'

Kinetochore is 

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

  1. Granule within centromere

  2. Surface of centromere

  3. Constriction near chromosome end

  4. End of chromosome

Show answer
Correct Option: A
Explanation:
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.
The kinetochore is a proteinaceous structure that assembles at the surface of the centromere which forms the site for binding of spindle fibres during cell division.
So, the correct answer is 'Surface of centromere'.

Telomeres

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

  1. Initiate RNA synthesis

  2. Help chromatids to move towards poles

  3. Seal ends of chromosomes

  4. Identify correct members of homologous pairs of chromosomes.

Show answer
Correct Option: C
Explanation:
  • 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.
  • These chromosomes have a repetitive nucleotide sequence at each end of chromosomes. 
  • It seals and protects each end of the chromosomes from deterioration or fusion with the neighbouring chromosomes during cell division.
  • So, the correct answer is 'Seal ends of chromosomes'.

A constriction on the chromosome is

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

  1. Centromere

  2. Centrosome

  3. Centriole

  4. Chromomere.

Show answer
Correct Option: A
Explanation:
  • 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.
  • It is responsible for the transfer of replicated chromosomes into the two daughter cells during the cell division.
  • So, the correct answer is 'Centromere'

Satellite means

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

  1. Terminal part of the chromosome beyond secondary constriction

  2. Terminal part of the chromosome beyond primary constriction

  3. Terminal part of chromosome beyond tertiary constriction

  4. None of the above

Show answer
Correct Option: A
Explanation:
  • Satellite chromosomes or SAT chromosomes are those chromosomes which have secondary constrictions other than a centromere.
  • The terminal end of the chromosome present beyond the secondary constriction is called satellite which is attached to the chromosome by a thin thread called chromatin.
  • So, the correct answer is 'Terminal part of the chromosome beyond the secondary constriction'.