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

If a newly born baby boy had a karyotype 23 + 23 + 23 chromosomes or 23 + 24, it would be

  1. within the range of normal

  2. an irregular number of chromosomes

  3. a structural modification in the chromosomes of the boy

  4. A genetic modification in the chromosomes of the boy.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When there are complete multiples of sets (e.g. 23 + 23 + 23), the error is known as polyploidy. When there is an addition or loss of chromosomes within a set (e.g. 23 + 22 or 23 + 24), it is known as aneuploidy. Both result in medical aberrations.

Multiple choice

A 16 year girl is suffering from a chromosomal abnormality that causes her to be unusually short in stature (average 4'7), to have a webbed neck, and to generally lack feminine secondary sexual characteristics. This may be due to

  1. Triple-X syndrome

  2. Turner syndrome

  3. XYY syndrome

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

Women with Turner syndrome are essentially postmenopausal from early childhood and are sterile because their ovaries do not develop normally and they do not ovulate.

Multiple choice

Which of the following statements is CORRECT of sex chromosome abnormalities in humans?

  1. They typically have benign effects and rarely are lethal.

  2. They have severe effects and are lethal.

  3. They do not depend upon gender.

  4. They cannot be diagnosed before birth of an organism.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Because sex chromosome abnormalities rarely result in an early death and their symptoms are often not severe, comparatively large number of people with these abnormalities survive to old age.

Multiple choice

A chromosomal abnormality that causes human males to have asexual to feminine body contours with large breasts, small penis, testes and prostate gland; comparitively little body hair and sterility is

  1. Klinefelter syndrome

  2. XYY syndrome

  3. Richard Speck syndrome

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

The feminizing effects of Klinefelter syndrome can be diminished if boys are treated regularly with testosterone injections from the age of puberty. As a result of this treatment, most become sufficiently ordinary in appearance to live in society without notice.

Multiple choice

What is the C value paradox?

  1. Haploid DNA content

  2. Huge variations in C values between species

  3. Diploid DNA content

  4. Constant C- value for all species

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

C value - the amount of DNA per haploid cell (usually expressed as picograms) or the number of kilobases per haploid cell. Eukaryotic organisms appear to have 2-10 times, as many genes as prokaryotes.

Multiple choice

A cell plate is laid during

  1. cytokinesis

  2. karyokinesis

  3. interphase

  4. none of these

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cytokinesis in terrestrial plants occurs by cell plate formation. Plant cells have walls, so cytokinesis cannot proceed with a cleavage furrow. Instead, during telophase, a cell plate forms across the cell.

Multiple choice

In meiosis, chromosome number becomes

  1. half of its parent chromosome

  2. same as that of parent chromosome

  3. one-fourth of parent chromosome

  4. None of the above

  5. -
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for sexual reproduction. Hence, it is called as reduction division.