1. Human Inheritance 1/5/15 Mr. Faia 6 th Grade Science

2. Traits Controlled by Single Genes What are some things we know about traits, alleles, phenotypes, and genotypes?

3. Traits Controlled by Single Genes Copy the Punnett Square for Widow’s Peak on p.113. What are the ratios for dominant and recessive phenotypes?

4. Multiple Alleles Some traits are controlled by a gene with more than 2 alleles. Multiple alleles are 3 or more forms of a gene code for a single trait.

5. Multiple Alleles How many alleles can 1 person have? What is an example of a trait with multiple alleles?

6. Multiple Alleles Punnett Square for Blood Types:

7. Traits Controlled by Many Genes Some human traits have many phenotypes because traits are controlled by many genes. Genes act as a group to produce a single trait.

8. Traits Controlled by Many Genes What are examples of traits controlled by many genes? How many genes control height in humans?

9. Effect of Environment Genes can be altered by the environment. What is an example of a trait that can be affected by the environment? How can it be affected?

10. Male or Female? Male – XY Female – XX ▫ Punnett Square:

11. Sex-linked Genes Genes on the X or Y chromosome are known as sex-linked genes Who is more likely to have a trait controlled by a recessive allele?

12. Sex-Linked Genes What is an example of a sex-linked trait controlled by a recessive allele? Copy the Punnett Square on p.117

13. Sex-linked Genes The mother is a carrier for color blindness Carrier is a person with 1 recessive and 1 dominant allele

14. Pedigrees Pedigree is a chart that can trace inheritance of traits What is another name for a pedigree?

15. Section Review Why do human traits such as height and skin color have many different phenotypes?

16. Section Review Explain why red-green colorblindness is more common in males than females.

17. Section Review What is a pedigree? How are pedigrees used?

18. Section Review Could two people with widow’s peaks have a child with a straight hairline? Could two people with a straight hairline have a child with a widow’s peak?