Difference Between Mitosis And Meiosis [American Edition]

What Is Mitosis?

Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as parent nucleus, typical of ordinary tissue growth. Mitosis consists of four basic phases that are prophase, metaphase, anaphase and telophase.

During mitosis, the chromosomes which have already duplicated, condensed and attached to spindle fibres that pull one copy of each chromosome to opposite sides of the cell. This result to two genetically identical daughter nuclei, the rest of the cell then continues to divide by cytokinesis to produce two daughter cells. It is also important to note that mitosis occurs only in eukaryotic cells, prokaryotic cells, which lack a nucleus, divide by a different process called binary fission.

What You Need To Know About Mitosis

1. Mitosis is the process of cell division in which the cell divides into two producing a replica, with an equal number of chromosomes in each resulting diploid cell.
2. In mitosis, each chromosome consists of two chromatids united by a centromere.
3. Takes place in the somatic cells of the body.
4. Occurs in both sexually as well as asexually reproducing organisms.
5. The cells usually divide only once.
6. Interface occurs prior to each division.
7. Prophase division stage is relatively simple.
8. The duration of prophase is short, usually a few hours.
9. The two chromatids of a chromosome do not exchange segments during prophase.
10. The cell divides only once and the chromosomes also divide only once.
11. Pairing of chromosomes does not occur in mitosis.
12. In mitosis, division of the centromeres takes place during anaphase.
13. Similar chromosomes move towards the opposite poles in anaphase.
14. Spindle fibers disappear completely in telophase.
15. Chromosome number remains constant at the end of mitosis.
16. Mitosis takes part in healing and repair.
17. During anaphase chromosomes are single stranded.
18. The arms of the prophase chromatids are close to one another.
19. The chromosome separates simultaneously during anaphase.
20. Two chromatids of chromosome are genetically similar. In other words, the genetic constitution of the daughter cells is identical to that of the parent cells.

Also Read: Difference Between Gametic, Zygotic And Sporic Meiosis

What Is Meiosis?

Meiosis is a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. Just like mitosis, meiosis the cell divides through four stages that are, prophase, metaphase, anaphase and telophase.

In meiosis, the chromosome or chromosomes duplicate during interphase and homologous chromosomes exchange genetic information (crossover) during the first division, called meiosis I. The daughter cells divide again in meiosis II, splitting up sister chromatids to form haploid gametes. Two gametes fuse during fertilization, creating a diploid cell with a complete set of paired chromosomes.

What You Need To Know About Meiosis

1. Meiosis is the process of cell division in which the numbers of chromosomes are produced by half through separation of homologous chromosomes, producing two haploid cells.
2. In meiosis, the two homologous chromosomes from bivalents or tetrads. Each bivalent has four chromatids and two centromers.
3. Takes place in the germ cells.
4. Occurs only in sexually reproducing organisms.
5. There are normally two cell divisions, the first and second meiotic divisions.
6. Interface proceeds only in meiosis. It does not occur prior meiosis II.
7. Prophase stage is complicated and divides into leptotene, zygotene, pachytene, diplotene and diakinesis.
8. Prophase is relatively longer and may take days.
9. Chromatids of two homologous chromosomes exchange segments during crossing over.
10. There are two cell divisions but the chromosomes divide only once.
11. Pairing or synapsis of homologous chromosomes takes place that is during zygotene of prophase I and continues up to metaphase I.
12. In meiosis, there is no division of centromere during anaphase I. However; centromeres divide only during anaphase II.
13. Chromosomes that are not similar move towards the opposite poles both in anaphase I and Anaphase II.
14. Spindle fibers do not disappear completely in telophase I.
15. The chromosome number is reduced from the diploid to the haploid.
16. Meiosis takes part in the formation of gametes and maintenance of chromosome number of a species.
17. Chromosomes are double stranded in anaphase I, but single stranded in anaphase II.
18. The arms of the chromatids are widely separate in prophase II.
19. Short chromosomes separate early; separation of long chromosomes is delayed.
20. Two chromatids of chromosome are genetically different due to crossing over. In other words, the genetic constitution of daughter cells differs from that of the parent cell. The chromosomes of the daughter cells usually contain a mixture of maternal and paternal genes.

Also Read: Difference Between Chromatin And Chromatid

The Difference Between Mitosis And Meiosis In Tabular Form

Also Read: Difference Between Cytokinesis In Plants And Cytokinesis In Animals

What are the Similarities Between Mitosis and Meiosis?

• Both processes of cell division give rise to more than one cell.
• Both include breakdown of the nuclear membrane.
• Both depend on spindle fibers to move chromosomes around.
• Both involve cytokinesis at the end of division.
• Fundamental events and processes are same in both meiosis and mitosis.

Also Read: Difference Between Mitosis In Plant And Animal Cells

Summary

Mitosis is a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as parent nucleus, typical of ordinary tissue growth.

Meiosis on the other hand, is a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.