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 evs the journey of seeds vegetative propagation and seed dispersal seed dispersal seed dispersal and its methods

Which of the following is correct chronological order of the division taking place through an apical or embryo cell to a sixteen cell stage?

  1. Vertical division $\rightarrow$ Transverse division $\rightarrow$ Division at right angles to both the previous divisions $\rightarrow$ periclinal division
  2. Vertical division $\rightarrow$ Vertical division at right angles to the first division $\rightarrow$ Division at right angles to both the previous divisions $\rightarrow$ Periclinal divisions
  3. Vertical division $\rightarrow$ Transverse division $\rightarrow$ Periclinal division
  4. Vertical division $\rightarrow$ Vertical division at right angles to the first divisions $\rightarrow$ Transverse division $\rightarrow$ Periclinal division
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The development of the proembryo typically follows a specific sequence: initial vertical divisions, followed by transverse divisions, and then periclinal divisions to differentiate the layers.

Multiple choice biology reproduction in animals story of dolly, the clone sheep story of dolly, the clone process of cloning

Efforts to repeat the cloning of Dolly (the sheep) have been unsuccessful. The scientists who claim to have cloned Dolly have been challenged to produce additional evidence that Dolly is really derived from an adult cell (an originally claimed), rather than a foetal cell which might have contaminated the experiment (as the sceplor suggest). Which of the following could provide evidence that Dolly was created from an adult cell, rather than a foetal cell?

  1. Dolly's DNA fingerprints

  2. The heterozygosity of random pieces of Dolly's DNA

  3. The melting point of Dolly's DNA

  4. The length of Dolly's telomeres
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Dolly was important because she was the first mammal to be cloned from an adult cell. Her birth proved that specialised cells could be used to create an exact copy of the animal they came from. Dolly's DNA fingerprints could provide evidence that Dolly was created from an adult cell.
So the correct answer is 'Dolly's DNA fingerprint'.
Multiple choice biology reproduction in animals story of dolly, the clone sheep story of dolly, the clone process of cloning

Efforts to repeat the cloning of Dolly the sheep have been unsuccessful. The scientists who claim to have cloned Dolly have been challenged to produce additional evidence that Dolly is really derived from an adult cell (as originally claimed), rather than fetal cells which might have contaminated the experiment (as the skeptics suggest). Which of the following could provide evidence that Dolly was created from an adult cell, rather than a fetal cell

  1. Dolly's DNA finger prints

  2. The heterozygosity of random pieces of Dolly's DNA

  3. The melting point of Dolly's DNA

  4. The length of Dolly's telomeres

  5. Dolly's biological clock
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Telomeres are sections of DNA found at the end of each chromosome. When the chromosomes are replicated during cell division a small portion of the telomeres are lost and thus, they get shorter with the animal's age due to cell division. This led to speculation in the press that Dolly's death was that she could have been born with a genetic age of six years, the same age as the sheep from which she was cloned. One basis for this idea was the finding that Dolly's telomeres were short, which is typically a result of the aging process.

Multiple choice biology selection and evolution phylogeny cladistics speciation

The red viscacha rat has almost twice as many chromosomes as one of its closest relatives, the mountain viscacha rat.

What mechanism most likely resulted in the evolution of the red viscacha rat?

  1. Errors in replication

  2. Errors in meiosis

  3. Environmental adaptations

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

The doubling of its chromosome number was presumably by errors in mitosis or meiosis within the animal's reproductive organs.A comparison of the chromosomes of the red viscacha rat and the mountain viscacha rat suggested that the chromosomes of the red viscacha rat increased relatively rapidly (in evolutionary terms) due to a diverse set of highly repetitive elements. So, the correct answer is " Errors in meiosis".

Multiple choice different stages of growth reproductive system in humans division for growth and reproduction human system biology

Which of the following process can be related to ageing? 

  1. Mutation

  2. Chromosomal abbreviations

  3. Genetic recombinations

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

Ageing involves accumulation of cellular damage. Mutations in DNA accumulate over time and contribute to aging. Chromosomal aberrations (abbreviations) are structural changes that increase with age. Both processes are linked to ageing.

Multiple choice biology division for growth and reproduction cell membrane and cell wall cell wall cell division in embryo development structure of chromosome, cell cycle and cell division component of the cell different types of reproduction reproductive health of humans need of family planning tissues of animals mitosis reproductive health

Cell cycle was divided into  four stages i.e. G$ _1$, S, G$ _2$, M by

  1. W. Flemming

  2. Strass burger

  3. Howard and Pelc

  4. Farmer
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Howard and Pelc divided cell cycle in four stage. The cell cycle is an ordered set of events, culminating in cell growth and division into two daughter cells. Non-dividing cells not considered to be in the cell cycle. The stages  are G$ _1$-S-G$ _2$-M. The G$ _1$ stage stands for "GAP 1". The S stage stands for "Synthesis". This is the stage when DNA replication occurs. The G$ _2$ stage stands for "GAP 2". The M stage stands for "mitosis", and is when and cytoplasmic division occur.

Multiple choice botany cell theory, cell specialization, and cell replacement number and shape of cells unicellular and multicellular organisms diversity and classification in animals

Forthe formation of diploid cells from haploid cells, colchicine is used to

  1. Stop the spindle fibres formation

  2. Replicate DNA twicely in one cell cycle

  3. Stop the formation of centromere

  4. Stop the mitotic division
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Colchicine is an alkaloid that inhibits microtubule polymerization by binding to tubulin. This prevents the formation of spindle fibers during mitosis, leading to polyploidy.

Multiple choice microsporophyll vs megasporophyll plant kingdom biology

An angiospermic male plant with $24$ chromosomes in its pollen mother cells is crossed with female plant having $24$ chromosomes in its root cells. What would be chromosome number of embryo and endosperm respectively after the cross.

  1. $24$ and $48$
  2. $24$ and $24$
  3. $48$ and $72$
  4. $24$ and $36$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Pollen mother cells are diploid (2n=24), so n=12. The embryo is formed by the fusion of a male gamete (n=12) and the egg (n=12), resulting in 2n=24. The endosperm is formed by the fusion of a male gamete (n=12) and two polar nuclei (n+n=24), resulting in 3n=36.

Multiple choice evs - i growth and personality development heredity and other supporting factors for development all together community work and its importance

What is called the unit of heredity?

  1. Genes

  2. Alleles

  3. Cells

  4. Chromosomes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
A. Genes are the unit of heredity.
B. Alleles are the alternate form of the gene.
C. Cells are fundamental structural and functional unit of living organisms.
D. Chromosomes carry genetic information in the form of genes.

So, the correct option is 'Genes'.
Multiple choice botany plant breeding plant breeding for disease resistance and insect resistance method of plant breeding for crop improvement plant breeding for food production

Cultivated tobacco, Nicotine tobacco has $2n=48$ chromosomes and is amphidiploids. Nicotine Sylvester's which one of the progenitors of Nicotine tobacco has $2n=24$ chromosomes and is diploid. It has contributed one genome to Nicottama tobacco. When these two species are hybridized, the critical chromosomal associations at meiosis in the hybrid will be.

  1. $24$ bivalents
  2. $12$ univalent
  3. $12$ bivalents
  4. $12$ bivalents $+12$ univalent
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice types of endosperms plant kingdom biology

If the leaf tip cells posses 14 chromosomes that how many chromosomes will be present in the endosperm of Pisum satium?

  1. 7

  2. 14

  3. 21

  4. 28
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leaves of a plant are diploid as it forms from zygote which is diploid itself.

The gametes are haploid means contain 7 chromosomes.
Endosperm is triploid means it has 21 chromosomes.
Gamete n=7
Leaf 2n=14
Endosperm 3n=21
So the correct option is '21'.

Multiple choice botany division for growth and reproduction difference between meiosis and mitosis meiosis the origin of cells and cell division

Cell division is tightly regulated, which of the following is true regarding mitosis or meiosis.
I. Mitosis shows no homologous pairing.
II. There is no S phase between meiosis I and II.
III. Meiosis centromeres do not divide at anaphase I.

  1. I and III only

  2. I and II only

  3. II only

  4. I, II and III
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Homologous pairing occurs in meiosis when homologous chromosomes come closer and synapsis occur leading to homologous pairing.

S phase occurs between G1 and G2 phase not between meiosis1 and meiosis2.
At anaphase I, sister chromatids remain attached to their centromeres, so they do not divide at this stage.
So the correct option is 'I, II and III'

Multiple choice botany division for growth and reproduction difference between meiosis and mitosis meiosis the origin of cells and cell division

Which of the following can not be used to differentiate meiosis with mitosis?

  1. Replication of chromosome before division

  2. Exchange of genetic material

  3. Formation of tetrad
  4. $2$ & $3$ both
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Answer is A. Replication of chromosome some before division

can not be used to differentiate meiosis with mitosis because it is the process which is done in interphase. And interphase are same in both meiosis and mitosis. 

Multiple choice botany division for growth and reproduction difference between meiosis and mitosis meiosis the origin of cells and cell division

A cell in mitotic prophase can be distinguished from a cell in meiotic prophase by?

  1. Formation of tetrad in a meiotic cell

  2. The terminalisation of chiasmata in late prophase of mitosis

  3. Zipping in early prophase of mitosis

  4. Presence of only half as many chromosomes in the meiotic cell
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The formation of tetrad is a special characteristic of Prophase 1 of meiosis 1.

The homologous pair aligns with each other and gets ready for crossing over.
So, the correct option is 'Formation of tetrad in a meiotic cell'.