Notes – Meiosis
Meiosis Terms Meiosis = the process of cell division that is used to produce gametes
Meiosis Terms Haploid = having one copy of each chromosome Diploid = having two copies of each chromosome
Meiosis Terms
Meiosis Terms Chromosome = a molecule of DNA that contains many genes Homologous chromosome = chromosomes that have the same genes but different alleles
The process of Meiosis
The process of Meiosis The nuclear membrane breaks down and chromosomes condense from chromatin
The process of Meiosis Homologous chromosomes line up in the middle of the cell
The process of Meiosis Homologous chromosomes line up in the middle of the cell Crossing over occurs: pieces of homologous chromosomes are exchanged
The process of Meiosis Homologous chromosomes separate and the diploid cell divides into 2 haploid cells
The process of Meiosis The two haploid cells each contain chromosomes that have two sister chromatids
The process of Meiosis The sister chromatids in each haploid cell separate, the cells divide and 4 haploid cells are formed
The process of Meiosis The sister chromatids in each haploid cell separate, the cells divide and 4 haploid cells are formed Each of the 4 cells is genetically unique
Meiosis: Tradeoff Close your notebooks 1 2 Close your notebooks In your own words, tell your neighbor what happens… Start with people by the door, then switch 3 4 5
Meiosis: Everybody Writes 1 2 Close your notebooks In your own words, write what happens… 3 4 5
Think … pair-share Why is this diagram misleading? Ask students: Why is this diagram misleading? Answer: the resulting cells are genetically unique due to crossing over rather than sets of two identical cells
Mitosis vs. Meiosis xxx
Mitosis vs. Meiosis Pair-share: compare mitosis and meiosis [3]
Mitosis vs. Meiosis Similarities: Differences: Diploid cells divide in both Differences: Meiosis results in 4 haploid cells whereas mitosis results in two diploid cells Meiosis results in genetically unique cells whereas mitosis results in genetically identical cells Meiosis involves homologous chromosomes pairing up and crossing over; mitosis does neither Meiosis involves two rounds of cell division whereas mitosis involves one round of cell division