Notes Meiosis Meiosis Terms Meiosis the process of

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 1. The nuclear membrane breaks down and chromosomes condense from chromatin

The process of Meiosis 2. Homologous chromosomes line up in the middle of the cell

The process of Meiosis 2. Homologous chromosomes line up in the middle of the cell • Crossing over occurs: pieces of homologous chromosomes are exchanged

The process of Meiosis 3. Homologous chromosomes separate and the diploid cell divides into 2 haploid cells

The process of Meiosis 4. The two haploid cells each contain chromosomes that have two sister chromatids

The process of Meiosis 5. The sister chromatids in each haploid cell separate, the cells divide and 4 haploid cells are formed

The process of Meiosis 5. 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

1 Meiosis: Tradeoff • Close your notebooks • In your own words, tell your neighbor what happens… • Start with people by the door, then switch 2 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?

Mitosis vs. Meiosis • xxx

Mitosis vs. Meiosis • Pair-share: compare mitosis and meiosis [3]

Mitosis vs. Meiosis • Similarities: – 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