1. Patterns of Inheritance
Chapter 8

2. Mendel the monk studied inheritance
keys to his success:

3. Mendel’s experiment
true-breeding.

4. Mendel’s experiment
Cross true-breeding parent plants that differ in only one trait
Let the offspring self-fertilize
Collect and analyze results from 1st and 2nd generations.

5. Results of monohybrid cross
Where did the white flower come from?!

6. Mendel’s conclusions
homozygous
heterozygous

7. Mendel’s conclusions
dominant;
recessive
genotype determines phenotype

8. Genotype determines phenotype:
the only way a recessive trait is expressed is when there are two copies of it

9. Homologous chromosomes

10. Regarding the dominant allele. . .
It does not mean
It just means

11. “Types” of inheritance
Complete dominance
Incomplete dominance
Codominance
Polygenic
Pleiotropy
Sex-linked

12. Complete dominance
This was Mendel’s conclusion

13. Incomplete dominance

14. Codominance
Example: sickle cell disease
Example: AB blood type

15. Polygenic inheritance

16. Pleiotropy

17. Sex-linked inheritance
A gene located on either sex chromosome

18. Sex-linked disorders
Affect mostly males, XY

19. Autosomal disorders
Recessive disorders
Dominant disorders