Tag: the mitotic cell cycle

Questions Related to the mitotic cell cycle

Match List I(Chromosome aberrations) with List II(consequences) and select the correct a answer using the codes given the lists.

List-I List-II
a. Intercalary deficiency $1$. chromosome ring formation at metaphase
b. Duplication $2$. Bridge and fragment formation
c. Para centric inversion $3$. Change in gene order
d. Translocation $4$. Two breaks followed by reunion and deletion
botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. A-$4$, B-$3$, C-$2$, D-$1$

  2. A-$4$, B-$3$, C-$1$, D-$2$

  3. A-$3$, B-$4$, C-$1$, D-$2$

  4. A-$3$, B-$4$, C-$2$, D-$1$

Show answer
Correct Option: A

Is chromosome refers to the ______________________.

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Chromosome which has been isolated from the rest of the complement

  2. Chromosome which has reached the equatorial plane earlier than the other chromosomes

  3. Tran located chromosome having identical arms

  4. Lagging chromosome which has not moved to either of the pole

Show answer
Correct Option: A

How are chromatin, chromatid and chromosomes related to each other?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Chromosomes are made up of chromatin

  2. Chromatin is made up of chromosomes

  3. Chromatin is made up of chromatids

  4. Chromosomes are made up of chromatids and chromatids are made up of chromatin

Show answer
Correct Option: D
Explanation:

Chromatin fibers are made from coiling of a long polynucleotide strand of a DNA to fit into the cell. Chromatids are made up of chromatin. The two sister chromatids are present in a chromosome.

So, the correct answer is option D. 

Choose the correct answer from the alternatives given:
In which part of the cell is DNA concentrated?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Chromosomes

  2. Cell wall

  3. Ribosomes

  4. Golgi body

Show answer
Correct Option: A
Explanation:

The chromosomes are the threadlike structures of nucleic acids found in the nucleus of most of the living organisms, carrying the genetic material in the form of genes. Thus DNA is concentrated in the chromosomes.

B. The cell wall is the structural component of the cell that gives shape to the cell.
C. Ribosomes and the Golgi body are the organelles present in the cell. Ribosomes help ion protein synthesis.
D. Golgi apparatus helps to process and bundle macromolecules like proteins and lipids that are synthesized in the cell.
Hence, the correct answer is 'Chromosomes'.

Choose the correct answers from the alternatives given :
The thread like structures that begin to radiate from each centromere by the end of prophase are

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. aster microtubules

  2. spindle microtubules

  3. kinetochore microtubules

  4. polar microtubules

Show answer
Correct Option: C
Explanation:

  • Prophase is the third stage of the mitosis where the chromosomes which were lined up at the metaphase plate in the metaphase are to be pulled towards the pole of the dividing cells.
  • The centrioles which are present at the pole of the dividing cells produce spindle fibers which are will help pull the chromosomes towards the pole .
  • These spindle fiber will attach to the kinetochore which is present with the centromere in the middle of the chromosome,
  • The kinetochore also produces microtubles which will attach will the incoming spindle fibers forming a bond so that they can be pulled towards the pole.
  • After reaching the pole the fibers will distangle from the kinetochore and disappear leaving the chromosomes to decondense and formation of the nuclear membrane around them .
  • Therefore the answer option 'kinetochore microtubules' is correct.

















Choose the correct answers from the alternatives given :
The centromere or primary constriction of the chromosome contains rings of protein that are intimately associated with a spindle fibre. These rings are called

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. asters

  2. secondary constrictions

  3. centrioles

  4. kinetochores

Show answer
Correct Option: D
Explanation:
  • The kinetochore is the region which is present in the center of the chromosome near the centromere or the primary constriction.
  • The spindle fibers which are formed from the centrioles are required to pulled the chromosome towards the poles of the dividing daughter cells.
  • The spindle fiber of the centrioles are attached to the kinetochore which is a protein ring or made up of protein which forms bonds with tubulin protein of the spindle fiber, so that the chromosomes can be pulled apart towards the poles. 
  • Therefore the answer option 'kinetochores' is correct.

Which is not a major function of the genetic material?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Store information

  2. Catalyse chemical reactions

  3. Replicate itself

  4. Undergo mutation

Show answer
Correct Option: B
Explanation:

Enzymes are present inside cells for catalyzing chemical reactions. While genetic material is present inside the nucleus as storage of information for all the cellular activities in the form of genes. Genetic material replicates during cell division. It can also undergo mutation during replication. 

So, the correct option is 'Catalyse chemical reactions'.

Select the correct option:

Which of the following stains is not used for staining chromosomes?

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Basic Fuchsin

  2. Safranin

  3. Methylene green

  4. Carmine

Show answer
Correct Option: B
Explanation:

Chromosomes are heavily coiled DNA, a DNA molecule is negatively charged and has to be therefore stained with basic dyes like Basic fuchsin, Methylene green and carmine.while safranin is used to stain cell walls of plants and bacteria (counter stain)

So, the correct answer is 'Safranin'

According to most recent studies, each chromosome consists of
botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. Single double helical DNA which is highly coiled and folded

  2. Variable number of DNA helices, depending upon the length of chromosome

  3. Many small DNA helices, which are joined by peptide linkages

  4. Small DNA helices, wrapped around each other like a rope

Show answer
Correct Option: A
Explanation:

There is a single, long, double-stranded, linear DNA molecule in a chromosome. The DNA contains biological and genetic information. It is highly coiled and folded, however this packing varies during the cell cycle.

So, the correct answer is 'Single double-helical DNA which is highly coiled and folded'.

Mark the correct option w.r.t. chromosomes.

botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

  1. mRNA + ribosomes

  2. mRNA + protein

  3. DNA + Protein

  4. Polyribosomes

Show answer
Correct Option: C
Explanation:

The nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

So, the correct option is 'DNA + protein.