1. Diploid and haploid phases of the life cycle

2. Results from Mendel’s experimental monohybrid cross
Punnett square
Segregation of alleles

3. Prediction for Mendel’s experimental dihybrid cross

4. Dihybrid cross results
Independent assortment of loci

5. Meiosis At which stage do daughter cells become haploid?
Where do segregation of alleles and independent assortment of loci occur?

6. Independent assortment of loci on different chromosomes
Minimum number of gamete types = 2n
In humans, n = 23
Gamete types from mother: 8,388,608
Gamete types from father: 8,388,608
Maximum chance that two children from the same parents will be identical: 1/70 trillion

7. Mendelian genetics explained by meiosis
Segregation of alleles
Independent assortment of loci

8. Mitosis vs. meiosis Mitosis Meiosis asexual sexual any cell
diploid cell
no pairing
homologs pair
daughters same as parents
daughters haploid; parents diploid

9. NON-independent assortment of loci
Linkage
NON-independent assortment of loci

10. Recombination Crossing over
Re-shuffles linked alleles