- Cell happen to be fundamental unit of life.
- New cells will arise from existing cells.
- A cell will divide to give rise to two cells and these two cells can form four cells and so on. This is termed as “Cell reproduction” or “Cell division“.
- Cell division usually occur by Mitosis or Meiosis .
Following are the few differences between Mitosis and Meiosis:
| Differences | Mitosis | Meiosis |
| Definition | Mitosis is type of cell division occurring in somatic cells to form to identical daughter cells. | Meiosis is type of cell division occurring in germ cells cells to form to four haploid cells with varied genetic information compared to parental cells. |
| Function | Forms all kinds of cells required for growth and repair. Do not form gametes or sex cells | Formation of gametes – Sperm and egg |
| Place of occurrence | Somatic cells | Germ or reproductive cells |
| No. of stages | one | Completes in two stages |
| Prophase | Simple and short | Longer with many sub stages |
| Crossing over | Absent | Present to form gametes with different genetic identity |
| Pairing of homologous chromosomes | No | Yes. Pairing observed from zygotene of prophase I till metaphase I. |
| Mother cell or parental cell | Can be haploid or diploid | Always diploid |
| Metaphase | centromere towards equatorial plate and ends of chromosomes point to poles | At metaphase I, Centromere in towards poles and Chromosome ends towards equatorial or metaphase plate. |
| Homologous chromosomes | Homologous chromosome are not separated. | Homologous chromosome gets separated at anaphase I. |
| Centromere division | Centromere division takes place at anaphase I. Sister chromatids gets separated. | Centromere division and sister chromatid separation takes place only at anaphase II |
| Spindle fibers | Completely disappear at telophase I | Doesn’t disappear completely by telophase I |
| Telophase I | Two copies of each chromosome (homologous chromosomes) end up at poles. | Single copy (but replicated ) of each chromosome (haploid) end up at pole at the end of telophase I |
| Chromosome number | Remains same as parental cell | Reduced to half ( 2n to n) |
| Type of reproduction | Asexual | Sexual |
| Daughter Cell | The genetic make up of daughter cells are identical to parental cell. (diploid) | The genetic constitution of daughter cells usually differs from parental cell due to crossing over – each chromosome will a mix of both paternal and maternal genes. Independent assortment of homologous chromosomes at metaphase I also adds to genetic constitution variation observed in embryo, formed after fertilization. Daughter cells formed are haploid. |
Discovered by | Walther Flemming | Oscar Hertwig |
Image Credit: Biology openstax