Question

Best stage to observe shape, size and number of chromosomes is
A. Interphase
B. Metaphase
C. Prophase
D. Telophase

Answer 1

Hint: The stage in which we can observe shape, size and number of chromosomes phase begins after prophase. A spindle tube is formed and the chromosomes are aligned in the centre of the equatorial plate. The chromosomes are attached to the spindle tube in the centre. The sister chromosomes of each chromosome are connected at a central point, but hands are free.

Complete answer:
Most cells divide more than once in a lifetime. Together, they go through a series of regular events that make up the cell cycle. The time from the end of one mitosis to the beginning of the next is called interphase. This is a step between the end of the last telophase and the next prophase. This is the longest period of cell division.
Mitosis is part of somatic cell division, which includes nuclear division (karyokinesis) and cytoplasmic division (cytokinesis).
> Prophase begins immediately after the interphase phase. The chromosomes resemble thin, coiled threads in the early prophase , but are shortened, coiled, and more visible in the middle phase. In the final phase the chromosomes appear more visible, are shorter and thicker and are doubled in length. Two chromatids on each chromosome located at the centromere are visible under a light microscope.
> Metaphase: This phase starts after prophase. The spindle tube forms and the chromosomes are aligned in the middle of the equatorial plate. The chromosomes are attached to the spindle tube at the centromere. In the beginning of metaphase lysis of the nuclear membrane occur and In the cell nucleus, the formation of a spindle and chromosome in the centre of the cell equator, the centrosome attaches to the fibers of the spindle, which form the spindle.
Chromosomes are clearly visible in the metaphase.
> Anaphase: This is the phase in which the chromatids in the centromere separate and move to opposite sides or poles. The chromatids on each chromosome become free at the centromere, but each chromatid is attached to the spindle tube.
> Telophase: When the chromosomes reach the poles, the final stage begins with telophase. The spindle tube collapses and forms a new nuclear membrane at each pole, which covers the chromosomes. The nucleus also reappears at each pole.
So from the above point it’s clear that metaphase is the best stage to study the morphology of chromosomes.
Hence, the correct option is Metaphase (B).

Note:
The centrosomes are arranged in a ring, together forming an intermediate plate. Depending on the location of the centromere, chromosomes look like V or J, or usually rods, depending on the shape of the metacentric, acrocentric, or telocentric chromosome. The metaphase chromosome is very coiled.
In metaphase Kinetochore microtubules align the chromosomes in the plane, forming a metaphase plate or an equatorial plate. The process of forming metaphasic plates is known as congression. The centrosome is located in the equatorial plane, and the chromosome arms move away from the equator this is known as auto-orientation. Small chromosomes remain in the center and large chromosomes occupy the periphery.