1. Holtzclaw – starts on page 99
Mendelian genetics
Holtzclaw – starts on page 99

2. Some vocabulary Gene – location on the DNA
Allele – alternate form of a gene – i.e. eye color
Trait – characteristic of an organism
Genotype – which alleles an organisms has – i.e. Bb vs BB
Phenotype – physical characteristics – i.e. Brown eyes

3. Patterns of inheritance are based on Chromosomes
Rules of probability can be applied to analyze passage of single gene traits from parent to offspring.

4. Patterns of inheritance are based on Chromosomes – cont.
Segregation and independent assortment of chromosomes result in genetic variation.
When the genes are on different chromosomes
Segregation - two copies of a gene (the alleles) separate when an individual makes gametes.
Independent assortment – A gamete can have any combination of chromosomes

5. Figure 8.6 Meiosis Accounts for Independent Assortment of Alleles

6. Patterns of inheritance are based on Chromosomes – cont.
Genes that are adjacent and close to each other on the same chromosome tend to move as a unit
the probability that they will segregate as a unit is a function of the distance between them.

7. Patterns of inheritance are based on Chromosomes – cont.
Pattern of inheritance
Monohybrid
Dihybrid
sex-linked
genes linked on the same homologous chromosome
can often be predicted from parent and offspring genotype/phenotype

8. Figure 8.5 Independent Assortment (Part 1)

9. Figure 8.5 Independent Assortment (Part 2)

10. A note about probability
Two coin tosses are independent events, each will come up heads ½ the time.
The probability that both will come up heads is:
½ x ½ = ¼
To get the joint probability, multiply the individual probabilities (multiplication rule).

11. Figure 8.8 Pedigree Analysis and Inheritance (Part 1)

12. Figure 8.8 Pedigree Analysis and Inheritance (Part 2)

13. Figure 8.9 Multiple Alleles for Coat Color in Rabbits

14. Figure 8.10 Incomplete Dominance Follows Mendel’s Laws (Part 1)

15. Figure 8.10 Incomplete Dominance Follows Mendel’s Laws (Part 2)

16. Figure 8.11 ABO Blood Reactions Are Important in Transfusions

17. Genetic disorders Can be attributed to Single gene Nondisjunction
Ex. Sickle anemia
Nondisjunction
Ex. Trisomy 21/Down syndrome
Sex-linked
Color blindness