Tag: botany

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Questions Related to botany

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

A pericentric inversion in chromosome involves _______________.

  1. One arm of a chromosome

  2. Both the arms of a chromosome

  3. Two different chromosomes

  4. More than two chromosomes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A pericentric inversion involves a chromosome segment that undergoes a 180-degree reversal and includes the centromere, thus affecting both arms of the chromosome. In contrast, paracentric inversions occur entirely within a single arm and exclude the centromere.

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

Lamp brush chromosomes found in certain organisms are directly related to metamorphosis. Which one of the following statements in this regard is incorrect?

  1. These are very large chromosomes

  2. These are actively engaged in RNA and protein synthesis and accumulation

  3. Lamp brush loops recede and these become normal looking chromosomal parts looking chromosomal parts

  4. They are compactly packed and have very high DNA content
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lampbrush chromosomes are giant chromosomes found in the oocytes of certain vertebrates. They are characterized by extensive loops that are sites of very high transcriptional activity (RNA and protein synthesis), meaning they are not compactly packed with high inactive DNA content as claimed by the incorrect statement.

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

$6$p $23$ in chromosome nomenclature indicates band number.

  1. $6$ in short arm of chromosome $23$
  2. $3$ in region $2$ of short arm of chromosome $6$
  3. $3$ in region $2$ of long arm of chromosome $6$
  4. $6$ in long arm of chromosome $23$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In standard cytogenetic chromosome nomenclature, a band designation such as 6p23 is read as chromosome 6, short arm (p), region 2, band 3. Thus, the digit 3 represents the band number in region 2 of the short arm.

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

Diagrammatic representations of a chromosome is known as ____________.

  1. Homotype

  2. Idiotype

  3. Merotype

  4. Karyotype
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
An ideogram is a diagrammatic representation of the karyotype that shows all of the pairs of homologous chromosomes in the nucleus. The pairs of chromosomes are lined up in order of size, so that the centromeres are aligned and the short arm is uppermost. An ideogram is a useful point of reference for analyzing mutations.
So the correct option is 'Idiotype'.
Multiple choice botany the mitotic cell cycle chromosome and its structure chromosome nucleus and chromosome

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
  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-$1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Intercalary deficiency involves deletion (4), Duplication involves change in gene order/dosage (3), Paracentric inversion leads to bridge/fragment (2), and Translocation involves ring formation (1).

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

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

  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
Reveal answer Fill a bubble to check yourself
D Correct answer
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. 

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

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

  1. Chromosomes

  2. Cell wall

  3. Ribosomes

  4. Golgi body
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

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

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

  1. aster microtubules

  2. spindle microtubules

  3. kinetochore microtubules

  4. polar microtubules
Reveal answer Fill a bubble to check yourself
C Correct answer
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.