Human Body

  Meiosis :-      (reduction division)    ·        Production of offspring by sextual reproduction includes the fusion of gametes ·        Gametes are formed from specialised diploid cells . this specialised  kind of cell division that reduces the chromosome number by half. ·        significance of meiosis: v   An essential process in all sexually reproducing animals. v   Maintain diploidity of zygote (i.e. maintenance of chromosomal v   number in zygote) v   Meiosis show crossing over, resulting in genetic recombination. v   Meiosis show increased incidences of mutation (sudden changes in v   genetic material) Meiosis involves two rounds of cell division giving rise to four daughter cell.  these two rounds of cell division are called: - ·        MEIOSIS-I Prophase-I M...

 Types of cell Division :- 1.       MITOSIS 2.       MEIOSIS MITOSIS:-( Equational division ) Mitosis cell division was 1 st observed by Walther Flemming in animal cell. It helps in the growth of the organisms by increasing in their size ,shape and volume hence its ak “growth division’’ It occurs in somatic cell so it also called as “somatic cell division’’ The cell cycle is divided into two phases: 1. Interphase 2.   M   phase ( mitosis phase)        Karyokinesis =nuclear division        Cytokinesis=Division of cytoplasm Significance of mitosis: Maintains nucleo-cytoplasmic ratio between parent and daughter cells. Maintains qualitative and quantitative ratio of genetic material b/w parent cell & daughter cell. Helps in growth of multicellular organisms. Helps in reproduction of unicellular organisms. Brings about regeneration of lost body parts in some animals. Helps in repairing ...