Question

Anastral mitosis is found in
(a) Animals
(b) Higher plants
(c) Bacteria
(d) Cyanobacteria

Answer 1

Hint: Anastral mitosis is seen in the kingdom that is a part of a ‘Two Kingdom’ system of classification developed in Linnaeus' times. This is the kingdom with an only autotrophic mode of nutrition.

Complete answer:
Anastral mitosis is found in higher plants. Let’s look into the cell division in detail to understand better.
- Cell division is considered a very important process in all living organisms.
- The ‘cell cycle’ is the sequence of events by which a cell duplicates its genome, then forms the other constituents of the cell and ultimately divides into two daughter cells.
The cell cycle is divided into two phases:
M phase (Mitosis phase): represents the phase when the actual cell division or mitosis occurs.
Interphase: represents the phase between two consecutive M phases.
M Phase:
- It is also called equational division.
- For convenience, mitosis has been divided into four stages of nuclear division or karyokinesis. They are Prophase, Metaphase, Anaphase, and Telophase.
- In prophase, the centrosome which has undergone duplication during interphase begins to move towards opposite poles of the cell. Each centrosome radiates out microtubules called asters. The two asters together along with spindle fibres form a mitotic apparatus.
- In higher plants, however, asters are not formed in the mitotic apparatus. This arrangement of the spindle is called acentric or anastral.
So, the correct answer is higher plants.

Note:
- M phase is called equational division because the number of chromosomes in the parent and progeny cells is the same.
- In dividing animal cells, the two poles of the spindle bear asters. Hence, this spindle is called amphiaster or centric.