mitosis and meiosis

• Meiosis is involved in the formation of gametes (sex cells), while mitosis is involved in the growth and repair of body cells.
• Interphase consists of three parts: G1, S phase, and G2.
• Eukaryotic cells spend most of their time in the interphase.
• G1 phase: Cell growth.
• S phase: DNA replication
• G2 phase: more cell growth
• Prophase: Chromosomes condense, spindle microtubules begin to form
• Metaphase: chromosomes line up in the center,
• Anaphase: sister chromatids are pulled apart
• Telophase: chromosomes decondense, nuclear envelope reforms, cells divide into two daughter cells
• Cytokinesis: division of the cytoplasm, differs in plant and animal cells
• Plant cells cytokinesis: cell plate
• Animal cells cytokinesis: cleavage furrow
• Diploid cells: have 46 chromosomes
• Haploid cells: have 23 chromosomes
• Spermatogenesis: produces sperm, takes place in the male testicles
• Oogenesis: produces egg, takes place in the ovaries of female
• Eukaryotic cells spend most of their time in the interphase.
• Meiosis is a process that separates homologous chromosomes.
• In meiosis 1, each daughter cell has one pair of homologous chromosomes that consists of 2 sister chromatids.
• In meiosis 2, these sister chromatids are separated and each cell only has 1 independent chromatid.
• Crossing over happens in prophase 1.
• The purpose of meiosis 1 is to give the daughter cells 1 pair each of homologous chromosomes.
• The purpose of meiosis 2 is to separate these homologous chromosomes into independent chromatids, producing 4 cells with 1 independent chromatid.
• Prophase 1 in meiosis involves the separation of homologous chromosomes by crossing over, the duplicated chromosomes condense, spindle fibers appear.
• Prometaphase 1 in meiosis involves the attachment of spindle fibers to the chromosomes thanks to the centromeres.
• Metaphase 1 in meiosis involves homologous chromosomes lining up in the center, independent assortment occurs where maternal and paternal chromosomes randomly line up on either side of the equator.
• Anaphase 1 in meiosis involves the separation of homologous pairs, the cells go from diploid to haploid; but the sister chromatids are still attached to one another.
• Prophase 2 and prometaphase 2 in meiosis are identical to Prophase 1 and Metaphase 1.
• Metaphase 2 in meiosis involves chromatids lining up in the center individually, not in pairs like metaphase 1.
• Anaphase 2 in meiosis involves sister chromatids individually being pulled into opposite directions of the pole.
• Telophase 2 in meiosis is identical to telophase 1.