Difference between Mitosis and Meiosis
What is Mitosis?
It is the type of cell division, which makes sure the same variety of chromosomes in the daughter cells as that in the parent cells. Despite small differences, the major steps of mitosis are mostly similar in both plants and animals. However, to prevent confusion our statement will be based upon the animal cell.
The mitosis occurs in haploid as well as in diploid cells in nearly all parts of the body when needed. Mitosis is a continuous process; however, it can be divided into two phases, i.e., karyokinesis, which involves the division of the nucleus, and cytokinesis which describes the division of the whole cell.
What is Meiosis?
Meiosis is a special kind of cellular division in which the number of chromosomes in daughter cells is reduced to half, as compared to the parent cell. In animals at the time of gamete formation, while in plants when spores are generated.
Each diploid cell after meiosis produces 4 haploid cells, because it involves two consecutive divisions after single replication of DNA. Two divisions are meiosis I and meiosis II. The initial meiotic division is the reduction division, whereas the second meiotic department is just like the mitosis.
Difference between Mitosis and Meiosis
Character | Mitosis | Meiosis |
Discovered by | Walther Flemming | Oscar Hertwig |
Reduction Division | Not a reduction division | A reduction division |
Chromosome Number | Remains constant | Reduced to half |
Prophase | Simple because there are no arrangement of homologous chromosomes | Complicated and divided into five sub-stages due to the arrangement of homologous chromosomes |
Number of Divisions | One mitotic division | Two meiotic divisions |
Pairing/Synapsis | Not occur | Occur |
Crossing Over | No crossing over | Crossing over by chiasmata formation |
Number of daughter cells | Two | Four |
Result into | Diploid cells(2n) | Haploid cells (n) |
Type of Cells Involved | Somatic cells | Sex cells/germ cells or gametes |
Type of Reproduction | Asexual Reproduction | Sexual Reproduction |
Genetically | Identical to parent cells | Different from parent cells |
Recombinants | Does not produce variations | Variations are produced by recombination/crossing over |
Purpose | To produce more cells especially during the early stages of development, Facilitate growth, repair, and replacement. | Takes part in the formation of gametes and maintains the number of chromosomes. |
Frequently Asked Questions
Q1: What is cell cycle?
Ans: The cell goes through a sequence of changes that involve a period of growth, replication of DNA, followed by cell division is called the cell cycle.
Q2: What is contractile ring?
Ans: A contracting belt of microfilaments are present in the middle of the cell. These microfilaments are called contractile ring.
Q3: Is interphase a resting phase?
Ans: No, interphase is not a resting phase but misleadingly termed as resting phase. It is the phase of great biochemical activity.
Q4: What are restriction points or check posts during cell cycle?
Ans: A checkpoint occurs late in the G1 before entering the S phase. If all internal and external factors are favorable, the cell replicates its DNA and then it divides.
Q5: What is the difference between mitosis of plant and animal cells?
Ans:
- Higher plants lack centrioles. They have an analogous region from which microtubules radiate.
- The shape of the plant cell does not change due to the cell wall.
- At cytokinesis, animals form contractile ring but plants form phragmoplast which is formed from vesicles of the Golgi complex.
Q6: What is the significance of meiosis?
Ans:
- The number of chromosomes restores at fertilization and chromosomes remain constant generation after generation.
- Due to crossing over and random assortment of chromosomes, there are new recombinants that provide genetic diversity or variability to individuals.