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 botany classical genetics variation and its type natural selection introduction to genetics

The major/ ultimate source of variations are

  1. Polyploidy

  2. Mutations

  3. Chromosome aberrations

  4. Segregation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Ultimate source of variation is MUTATION and nothing else. Mutations are mistakes that occur in DNA sequence of genome:
  • Point mutation e.g. nonsense and missense mutations
  • Frame-shift mutation e.g. insertion or deletion mutations
Any change in genetic DNA will be translated into a defect in the corresponding protein. Thus mutation is responsible for appearance of a phenotypic variation. Such a variation may help the organisms carrying the new variation to survive better. If it produces more progeny the variation will appear in more members. Variations which provide adaptive advantage get selected by nature, thus help organisms to evolve.

So, the correct answer is 'Mutations'.
Multiple choice biology water absorption and ascent of sap in plants transport of water across plants habit of plants plant classifications

Join properly Column-I and Column-II.

Column-I Column-II
(a) Henking $(1)$ Study of chromosomes in plants
(b) Bridges $(2)$ Environmental effect of sex determination
(c) Baltzer $(3)$ X-body
(d) Allen $(4)$ Law of genetic balance
  1. a-$4$, b-$3$, c-$2$, d-$1$
  2. a-$3$, b-$2$, c-$4$, d-$1$
  3. a-$3$, b-$4$, c-$2$, d-$1$
  4. a-$1$, b-$2$, c-$3$, d-$4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology organization of life the cell structure cytoplasm number and shape of cells

Cytokinesis is a division of:

  1. Cytoplasm

  2. Nucleus

  3. chromosomes

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

Cytokinesis is the process of division of Cytoplasm. "Kinesis" means division and "cyto" refers to cytoplasm. it occurs during cell division. It is variable from plant cells to animal cells.

So, the correct option is 'Cytoplasm'.

Multiple choice botany mendel's law of inheritance genetics terminology similarities and dissimilarities in organisms introduction to genetics

Which of the following is considered as physical and chemical unit of heredity?

  1. Gene

  2. Chromosome

  3. Nucleotide

  4. Codon

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

A gene is a locus (or region) of DNA which is made up of nucleotides and is the molecular unit of heredity. It controls the development and function of all organs and all working systems in the body. Genes are passed from parent to offspring; the combination of these genes affects all aspects of the human body, from eye and hair colour to how well the liver can process toxins. 

Therefore, the correct answer is option A.

Multiple choice botany mendel's law of inheritance genetics terminology similarities and dissimilarities in organisms introduction to genetics

Which of the following is considered as unit of inheritance?

  1. Gene

  2. Chromosome

  3. Nucleotide

  4. Codon

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

Genes are the segment of DNA which carries information from parents to offsprings. It is the basic unit of heredity as they code for proteins which in turn determine the genetic traits. Genes are a continuous stretch of DNA and are linearly arranged on chromosomes. Chromatids are two identical parts of a duplicated chromosome. Nucleotides serve as a monomer of DNA. Codon is a base triplet of the gene that specifies specific amino acid. The correct answer is A.

Multiple choice botany mendel's law of inheritance genetics terminology similarities and dissimilarities in organisms introduction to genetics features of human body and sign language

Biological unit controlling heredity is ___________.

  1. Genome

  2. Chromosome

  3. Genotype

  4. Gene.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A.Genome – a set of chromosome in an organism in a body.

B.Chromosome – Dark coloured, small rod like structures, appear in the dividing nucleus is called Chromosome.

C.Genotype – It is the representation of an individual’s genetic constitution with respect to a single character or set of characters.

D.Gene - A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins. However, many genes do not code for proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases.

So, the correct option is ‘Gene’.

Multiple choice botany mendel's law of inheritance genetics terminology similarities and dissimilarities in organisms introduction to genetics features of human body and sign language

According to modern concept, Mendel's factor is called as_____________

  1. Chromosome

  2. Gene

  3. DNA

  4. Chromatid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • According to the modern concept, Mendel's factor is called a gene. Mendel believed that heredity is the result of discrete units of inheritance, and every single unit (or gene) was independent in its actions in an individual’s genome. According to this Mendelian concept, inheritance of a trait depends on the passing-on of these units. For any given trait, an individual inherits one gene from each parent so that the individual has a pairing of two genes.
Multiple choice botany mendel's law of inheritance genetics terminology similarities and dissimilarities in organisms introduction to genetics features of human body and sign language

What is the correct sequence from least complex to most complex in terms of the amount of information they carry?

I. Chromosomes
II. Base pair
III. Codon
IV. Gene

  1. I $\rightarrow $ II$\rightarrow $ III $\rightarrow $ IV
  2. II $\rightarrow $ III$\rightarrow $ I $\rightarrow $ IV
  3. III $\rightarrow $ II $\rightarrow $ I $\rightarrow $ IV
  4. II $\rightarrow $ III $\rightarrow $ IV $\rightarrow $ I
  5. II $\rightarrow $ IV $\rightarrow $ II $\rightarrow $ I
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A base pair (II) carries least information as at least three bases together (base triplet) make a codon (III) which in turn code for an amino acid. Genes (IV) are the stretch of DNA and each gene codes for a particular protein. Many genes are linearly arranged on a chromosome which means that chromosomes carry information for many proteins.

Therefore, the correct answer is option D.

Multiple choice botany option b: biotechnology and bioinformatics dna transfer rdna technology - dna transfer and transformation biotechnology in agriculture

Which of the following is the advantage of meiotic recombination in diploids?

  1. Helps in maintaining chromosome length

  2. Ensures chromosome segregation

  3. Helps chromosomes to attach to the spindle microtubules

  4. Ensures new combinations of genetic traits
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Meiotic recombination is the result of crossover and independent assortment. Crossover is the exchange of genetic material between non-sister chromatids of a homologous pair that generate new genetic combinations; option D is correct. Telomeres are the structures present at the ends of linear eukaryotic chromosomes and have many tandem copies of a short oligonucleotide sequence with guanine residues in one strand and cytosine in the complementary strand. The G-rich strand has a few hundred nucleotides long overhang at the 3’ end which serves as the primer for its elongation by telomerase enzyme and thereby maintaining chromosome length; option A is incorrect. The independent assortment of non-homologous chromosomes during meiosis results in independent segregation of nonhomologous chromosomes; option B is incorrect. Centromere directs the formation of the kinetochore on its surface, a special protein structure that attaches to the microtubules in the mitotic spindle; option C is incorrect. The correct answer is D.

Multiple choice biology classification of plants thallophyta cryptograms kingdom plantae

In Ulothrix, meiosis takes place in 

  1. Cells of the filament

  2. Holdfast

  3. Zygote

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

Ulothrix being an haploid organism, shows zygotic meiosis. Zygote is the only diploid structure which undergoes meiosis to form four cells. Each develops into Ulothrix.

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Fastest phase of S-shaped growth curve is

  1. Lag phase

  2. Log Phase

  3. Stationary phase

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

  • S-shaped logistic growth curve includes 3 phases:
  • Lag phase - When some organisms are introduced in an area, the population growth begins slowly.
  • Log phase - The conditions are ideal and the maximum growth rate is reached.
  • Stationary phase - Growth rate begins to slow down as factors such as food, water and space become limiting.
Thus, the correct answer is 'Log phase.'

Multiple choice biology plant growth growth rates and conditions for growth population ecology growth and development

Incorrect about geometrical growth

  1. After mitosis both daughter cells retain the capacity of division

  2. Growth pattern follows sigmoid curve

  3. Less common than arithmetic growth in the plants

  4. Growth rapidly increases
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In geometrical growth both the progeny cells following mitotic cell division retain the ability to divide and continue to do so. However, with a limited supply of nutrients, the growth becomes slow which lead to the stationary stage. A sigmoid curve is the characteristic of organism living is the natural environment.

So the correct option is 'growth rapidly increases'