Difference between Mitosis and Meiosis
• Germ cells go through Meiosisand there are 2 • Somatic cells (body cells) go through Mitosis
divisions. and there is only 1 division.
• 4 cell daughters that are genetically different. • The two daughter cells are identical.
• Half number of chromosome of gametes
• Chromosome number of daughter is 2n
• Interactions of these cells arethe reasons for
What is male/women contribution in sexcells?
Male: Sperm or pollen and they do not transfer much.
Female: Egg contributes most or all of the cytoplasm to the zygote
Note: N in humans is 23. 2n IS 46 (diploid)
What happens in animal cycle?
The cell is in a diploid phase when undergoing mi tosis and after fertilization when is undergoing meiosis the cell
changes to haploid phase. (Refer to slide 4)
What happens in plant cycle?
There can be haploid/diploid cells that are multicellular. Diploid goes through meiosis to form fruiting body that
produces the haploid cells and those now can go through fertilization. (Pollen/eggs)
What happens in fungi cycle?
They can go through a diploid phase where they can be unicellular. Because of meiosis we get gametes that are
half the number of chromosomes.
Meiosis (Briefly explained in slide 5)
Meiosis 1: Replication of chromosomes and proteins in pre meiotic interphase.
• Prophase 1: condensation and homologous chromosomes pair up and exchange pieces of DNA (crossing
over) heading towards metaphase with microtubules starting to reach for the chromosomes
• Metaphase: homologous pairs aligning in the middle (not individual chromosomes)
• In anaphase and telophase the homologous pairs separate into different poles
• Cytokinesis is the separation into 2 new cells
• Metaphase: aligning of single chromosome and split in different axis of division where sister chrom atids
are not equal anymore
• After telophase 2 there are 4 completely different gametes.
What is gametogenesis?
Is a biological process by which diploid or haploid precursor cells undergo cell division and differentiation to form
mature haploid gamete