Tag: the mitotic cell cycle

Quizzes (1) Questions (86)

Questions Related to the mitotic cell cycle

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

Kinetochore is?

  1. Surface of centromere

  2. Trilaminar plate over centromere

  3. End of chromosome

  4. Constriction near chromosome end
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
Multiple choice botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

Somatic chromosome number is 40.What shall be chromosome number in the cells seminiferous tubule ?

  1. 40

  2. 20

  3. 10

  4. 40 and 20
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Somatic cell is diploid (2n) in nature. It is given that the number of somatic chromosomes is 40. Seminiferous tubules contain haploid (n) spermatozoa. These spermatozoa are haploid in nature.
Hence, the number of chromosomes in the cells of seminiferous tubules will be 20.
Thus, the correct answer is '20.'
Multiple choice botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

A pericentric inversion in chromosome involves _______________.

  1. One arm of a chromosome

  2. Both the arms of a chromosome

  3. Two different chromosomes

  4. More than two chromosomes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pericentric inversion involves a chromosome segment that undergoes a 180-degree reversal and includes the centromere, thus affecting both arms of the chromosome. In contrast, paracentric inversions occur entirely within a single arm and exclude the centromere.

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

Lamp brush chromosomes found in certain organisms are directly related to metamorphosis. Which one of the following statements in this regard is incorrect?

  1. These are very large chromosomes

  2. These are actively engaged in RNA and protein synthesis and accumulation

  3. Lamp brush loops recede and these become normal looking chromosomal parts looking chromosomal parts

  4. They are compactly packed and have very high DNA content
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lampbrush chromosomes are giant chromosomes found in the oocytes of certain vertebrates. They are characterized by extensive loops that are sites of very high transcriptional activity (RNA and protein synthesis), meaning they are not compactly packed with high inactive DNA content as claimed by the incorrect statement.

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

$6$p $23$ in chromosome nomenclature indicates band number.

  1. $6$ in short arm of chromosome $23$
  2. $3$ in region $2$ of short arm of chromosome $6$
  3. $3$ in region $2$ of long arm of chromosome $6$
  4. $6$ in long arm of chromosome $23$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In standard cytogenetic chromosome nomenclature, a band designation such as 6p23 is read as chromosome 6, short arm (p), region 2, band 3. Thus, the digit 3 represents the band number in region 2 of the short arm.

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

Diagrammatic representations of a chromosome is known as ____________.

  1. Homotype

  2. Idiotype

  3. Merotype

  4. Karyotype
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
An ideogram is a diagrammatic representation of the karyotype that shows all of the pairs of homologous chromosomes in the nucleus. The pairs of chromosomes are lined up in order of size, so that the centromeres are aligned and the short arm is uppermost. An ideogram is a useful point of reference for analyzing mutations.
So the correct option is 'Idiotype'.