Question

Shape of chromosomes is determined by position of
A. Centrosome
B. Centromere
C. Telomere
D. Micromere

Answer 1

Hint: During mitosis, which is a common type of cell division, this structure is attached to the chromosome through spindle fibres. This structure can be seen in the electron microscopy and when stained this structure is shown as lightly stained attached to the two newly formed chromatids.

Complete answer:
The shape of the chromosomes is determined by the position of the centromere
A different phase of cell division of chromosomes shows having different shape and size
When the centromere is placed in centred the two chromatids become short, thick and are attached to the spindle fibres.
When the centromere is placed near the end of the pole one arm becomes short arm end and another end becomes long arms end which can be seen in telocentric.
The position of the centrosome in chromosomes is named as metacentric where both the arms are of the same size.
In sub metacentric the chromosomes one chromatid arm is short other is comparably longer
In acrocentric one arm is longer and the other arm beyond centromere is very short
In telocentric the arm before centromere is long and beyond the centromere no chromosome is present
They look like a rod in shape as the centromere is at the end of chromosomes.
These events show how centromeres determine the shape of a chromosome.

Correct option is B) Centromere.

Note: This structure can be seen in metaphase and anaphase. It is also known to be primary constriction which can be seen easily in microscopy as a lightly stained, small round structure such as a small round ball attached to the chromosome. Their function is to attach both chromatids together in place with a link to a spindle fibre.