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

Animal Cell and Plant Cells differ in their cytology is a well-known fact. The following two questions need to be answered based on the clarity of the cell doctrine and cellular function.

Which of the following options quotes the main difference between a dividing plant cell and an animal cell?

  1. Type of spindle formation

  2. Coiling of chromosome

  3. Chromosome movement

  4. Cell plate formation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It was Mathias Schwann who brought out the difference between the plant cell and animal cell based on the microscopic observation of plant cells provided by Schleiden. Schwann, Schleiden and Virchow are the three contributors of The Cell Theory. Schleiden was a botanist and did not observe animal cells. Virchow contributed with his famous doctrine of “omnis cellula e cellula- Cells originate from existing cells”. Schwann experimented both with animal as well as plant cells and marked the difference as “Animal cells do not have a cell wall”. The division cycle of both the animal and plant cells proceeds through same cycles, except for the cytokinesis where plant cells have a special structure formed known as cell plate, which will later become the cell wall. 

Multiple choice

Which of the following is an example of hypoploidy?

  1. Down's syndrome

  2. Patau's syndrome

  3. Edward's syndrome

  4. Turner's syndrome

  5. Klinefelter syndrome
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Turner's syndrome, 45,X, encompasses several conditions in human females, of which monosomy X (absence of an entire sex chromosome, the Barr body) is most common. It is an example of hypoploidy.

Multiple choice

Chromosomal theory of inheritance was based on

  1. segregation of genes

  2. diploidy and haploidy

  3. sex linkage

  4. presence of sex chromosomes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The behaviour of homologous chromosomes during meiosis (their segregation) and independent assortment) and their reunion in fertilisation confirmed that the genetic material occurs in the chromosomes and formed the basis of chromosomal theory of inheritance. Which is propounded independentaly by Sutton and Boveri in 1902. A karyotype composed of two identical sets of dissimilar chromosomes is called diploid set and of single set of chromosomes is called haploid set.

Multiple choice

Mongolism is also known as

  1. Turner's syndrome

  2. Hypothalmic syndrome

  3. Klinefelter's syndrome

  4. Down's syndrome
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Down's syndrome or mongolism or mongolian idiocy is caused by the trisomy on chromosome number 21. Thus, the egg possesses 24 chromosomes instead of 23 and the offspring has 47 chromosomes (45 + XY in male, 45 + XX in female). 

Multiple choice

Which of the following statements are not true?

  1. Pseudogenes are inactive copies of protein-coding genes.
  2. About 80% of the human genome consists of repetitive DNA sequences.
  3. The human reference genome is a diploid sequence.
  4. The total length of the human genome is over 3 billion base pairs.

  1. 1 and 2

  2. 1 and 3

  3. 1 and 4

  4. 2 and 3

  5. 2 and 4
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

About 8% of the human genome consists of repetitive DNA sequences, termed as tandem repeats or tandem DNA arrays. The human reference genome (HRG) is a haploid sequence. Each chromosome is represented once.

Multiple choice

What Cycas shows:

  1. Simple polyembryony

  2. Cleavage polyembryony

  3. Simple and cleavage polyemryony both

  4. No polyembryony

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

In simple polyemryony many eggs may be fertilized simultaneously resulting into the formation of many embryos.

Multiple choice

Which of the following is true about binary fission?

  1. It involves the division of nucleus only.

  2. It involves the division of nucleus and then the complete cell.

  3. It involves the division of nucleus into four nuclei.

  4. The division of nucleus does not take place, but the cell divides to form daughter cells.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In binary fission, first the nucleus divides into two nuclei followed by the division of the cell body into two.

Multiple choice

Chromosome number is

  1. fixed for a species

  2. fixed for a community

  3. fixed for a ecosystem

  4. fixed for a biosphere
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Chromosome number is fixed for a species. The lowest number is seen in Haplopapas gracilis (Asteracease), i.e. 2n = 4 and maximum in some Ophiglosum species (pteridophyte), i.e. 2n = 1656.