Biology

Cell Cycle and Chromosomes

1,348 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

Organisms with highest and least number of chromosomes respectively are ___________.

  1. Tympanoctomys barrerae and Myrmecia pilosula

  2. Myrmecia pilosula and Ophioglossum reticulatum

  3. Ophioglossum reticulatum and Myrmecia pilosula

  4. Tympanoctomys barrerae and Drosophila melanogaster

  5. Ophioglossum reticulatum and Tympanoctomys barrerae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ophioglossum reticulatum (2n=1260): Highest known number  of chromosomes in any life form Myrmecia pilosula (2n=2): 2 for females, males are haploid and thus have one; smallest number of chromosomes among all organisms.

Multiple choice

What happens in anaphase stage?

  1. Chromatids start moving towards the opposite poles.

  2. Chromatids start moving towards the equatorial line.

  3. Chromatids condense to form chromosomes.

  4. Crossing over takes place between the homologous chromosomes.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In anaphase stage, chromatids start moving towards the opposite poles, while the chromosomes are drawn to each side of the cell. The non-kinetochore spindle fibres push against each other, in a ratcheting action, that stretches the cell into an oval. 

Multiple choice

The characteristic feature of meiosis is that

  1. daughter cells have the same genetic information as the parent cell

  2. centromeres are divided at anaphase II

  3. homologous chromosomes do not cross over

  4. daughter cells have half the number of chromosomes as that of the parent cell (2n – n)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The characteristic feature of meiosis is that the daughter cells have half the number of chromosomes as that of the parent cell (2n – n).

Multiple choice

Discarding a non-needed member is called

  1. adenine

  2. abscission

  3. bacteriophase

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

A plant will abscise a part either to discard a member that is no longer necessary, such as a leaf during autumn, or a flower following fertilisation, or for the purposes of reproduction. Another form of abscission is fruit drop, when a plant abscises fruit while still immature, in order to conserve resources needed to bring the remaining fruit to maturity. If a leaf is damaged, a plant may also abscise it to conserve water or photosynthetic efficiency, depending on the 'costs' to the plant as a whole.

Multiple choice senescence senescence and death plant growth plant growth and development biology

The terminal phase of ageing is called as

  1. Dedifferentiation

  2. Senescence

  3. Abscission

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ageing is the result of a sequential switching on and off of certain genes. Ageing results in senescence. Senescence refers to a number of controlled processes which finally culminate in the death of the plant part. The senescence is considered as the last phase in the process of ageing. 

Thus, the correct answer is option B. 

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

How many divisions must occur in a cell of root tip to form 128 cells ?

  1. 128

  2. 127

  3. 64

  4. 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Root tip cells are somatic cells. Therefore, it will divide by mitotic division.
$1$ parent cell with form $2$ daughter cells. Then, we can calculate after $127$ divisions of cells it will form $128$ cells.
Therefore, the option (B) is correct.
Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

The process of cell death involving DNA cleavage in cells is known as

  1. Necrosis

  2. Apoptosis

  3. Cytokinesis

  4. Endocytosis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Apoptosis is the process in living cells which results in the death of cells that are damaged, attacked by pathogens, cancerous cell, abnormal cell, etc. Such cells are identified by the cells of the immune system followed by the production of proteins that kills the cell by DNA cleavage. It is also called programmed cell death. Thus the correct answer is option A. 
Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

Division of the nucleus is called ..........

  1. Cytokinesis

  2. Karyokinesis

  3. Replication

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Division of the nucleus is called karyokinesis. The process of partition of a cell's nucleus into the daughter cells during cell division is called karyokinesis. All the changes in a nucleus that occur during cell division are collectively termed as karyokinesis. It has four stages prophase, metaphase, anaphase, and telophase.

So the correct answer is "Karyokinesis".

Multiple choice mitosis structure of chromosome, cell cycle and cell division cell division biology cell division in embryo development division for growth and reproduction

All nuclear changes that occur during mitotic cell division are collectively called as

  1. Karyokinesis

  2. Cytokinesis

  3. Recombination

  4. Both A and B
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

All nuclear changes (Prophase, metaphase, anaphase, and telophase) that occurs during mitotic cell division are collectively called as karyokinesis. Mitotic cell division consists of two steps. The first step is karyokinesis where nuclear division takes place which is followed by cytokinesis i.e the division of cytoplasm takes place and individual daughter cells are formed. So, the correct answer is 'Karyokinesis'.

Multiple choice transgenic organisms biotechnology and its applications biotechnology and its application biology

Dolly sheep cloned by Dr. Ian Wilmut was genetically identical to

  1. The donor sheep which donated diploid nucleus

  2. The sheep which donated the egg cell

  3. The surrogate mother

  4. The sheep which donated haploid nucleus
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Dolly is the first sheep which was developed by the technique of cloning. 
  • The sheep was developed from the diploid body cell. The somatic cell from the mother sheep was taken and the nucleus was injected into the egg cell.
  • This egg cell was cultured and transferred to the surrogate mother. 
  • The sheep Dolly was identical in the characters with the mother who donated the diploid nucleus from the body cell. 
  • The genes from the mother cells were transferred to Dolly. 
  • Thus, the correct answer is option A.