question_answer 56)

  Differentiate between the events of mitosis and meiosis.

Answer:

                Mitotic cell division results into the increase in the number of cells that have same genetic  composition whereas meiosis has its importance in the life cycle of sexually reproducing organisms.

Mitosis	Meiosis
Event Prophase Chromomeres are not conspicuous. Prophase is of shorter duration.	Chromomeres are quite conspicuous. Prophase-I is of longer duration while prophase-II is very brief.
Prophase is simpler and is hardly distinguishable into substages.	Prophase-I is complicated and is divisible into five substages. Prophase-II is, however, very simple.
Each chromosome has two distinct  chromatids.	Chromosomes of prophase-I do not show distinct chromatids.
No bouquet stage is recorded.	Chromosomes of animals and some plants show convergence towards one side during early prophase-I. It is known as bouquet stage.
Chiasmata are absent.	Chiasmata or visible connections between  homologous chromosomes of bivalents are observed during diplotene, diakinesis (prophase-I) and metaphase-I.
Metaphase Centromeres produce a single metaphasic plate.	A double metaphasic plate is formed by centromeres in metaphase-I but only one  in metaphase-II.
Chromosomes are independent and do not show connections.	Homologous chromosomes are interconnected. Hence, the chromosomes occur in pairs or bivalents in metaphase-I. They are however, free in metaphase-II.
Only the centromeres lie at the equator. The limbs of chromosomes are oriented in various direction.	Limbs of the chromosomes mostly lie at the equator while the centromeres project towards the poles in metaphase-I.
A centromere is connected with both the spindle poles.	A centromere is connected to one spindle pole in metaphase-I, but both in  metaphase-II.
Two chromatids of a chromosome are genetically similar.	The two chromatids of a chromosome are often genetically different due to crossing  over.
Anaphase
A centromere splits length-wise to form two centromeres in the beginning of anaphase.	Centromeres do not divide during anaphase-I but do so in anaphase-II.
An aphasic chromosomes are single strande.	Chromosomes are double-stranded in  anaphase-I, but single stranded in anaphase-II.
Mitosis	Meiosis
Similar chromosomes move towards the opposite poles in anaphase.	Dissimilar chromosomes move toward the opposite poles both in anaphase-I and anaphase-II.
Telophase Telophase is longer and produces inter phase nuclei.	Telophase-I is shorter and nuclei now enter the inter phase.
Cytokinesis Cytokinesis follows every mitosis. It produces two new cells.	Cytokinesis often does not occur after first or reductional division. It is then simultaneous after second division resulting in four new cells.