1. Genetics EOC Remediation

2. Some definitions to know
Gregor Mendel - the Father of Genetics
Trait - a characteristic that can be passed to offspring
Genotype – the pair of genes that make up a trait (one from mom, one from dad)
Aa, AA, aa
Phenotype – What the trait looks like
Black or brown fur color

3. Independent assortment means that genes are separated during meiosis, and each egg and sperm is unique.

4. Punnett squares are used to predict the genotype and phenotype of the offspring

5. Punnet Squares and Ratios

6. A test cross is used to determine the genotype of an unknown parent

7. Types of Dominance Complete
One allele is dominant and one is recessive
B allele for black fur
b allele for brown fur
If the genotype is Bb, the fur would be black, because black is dominant

8. Practice crosses Flower Red is dominant White is recessive
Cross a homozygous dominant red flower with a heterozygous red flower.
What are the genotypic and phenotypic ratios?
Seeds
Green is dominant
Yellow is recessive
Cross a homozygous recessive yellow seed with a homozygous dominant green seed.
What are the genotypic and phenotypic ratios?

9. Types of Dominance Incomplete
When neither allele is dominant and the phenotype is intermediate or a blend of the two alleles.
R is the allele for red flowers
R’ is the allele for white flowers
The genotype RR’ would produce pink flowers

10. Incomplete Dominance Long water melon (LL) * Round watermelon (L’L’)
Do the cross
What is the genotypic ratio?
What is the phenotypic ratio?
Remember – The phenotype in this case has 3 possibilities, LL long : L’L’ round: LL’ oval

11. Types of Dominance Codominance
When both alleles are dominant and each allele is expressed in the trait
Type AB blood has both A and B antigens on it

12. Punnet Square For Blood TypesIA IB i i

13. Multiple alleles vs. polygenic inheritance
more than 2 forms of a gene
Bloodtype alleles IA IB i
Polygenic inheritance
When two or more genes work together to give you one trait
Ex. Hair and eye color

14. Sex linked genes are on the sex chromosomes (colorblindness and hemophilia)
XX = normal female
XhX = carrrier female
XhXh = hemophiliac female
A female who is a carrier does not have that trait! She is not sick at all. She won’t even know that she carries that gene.
XY = normal male
XhY = hemophiliac male
Males only have I X chromosome.
They cannot be carriers.
This is why sex linked disorders are more common in men

15. Pedigrees show the inheritance of traits through families

16. Hemophilia – Offspring of Queen Victoria

17. Chromosome map shows all the genes on single chromosome

18. Karyotypes show the complete set of chromosomes that a human has

19. Biotechnology Gel electrophoresis
Used in DNA fingerprinting to match DNA at a crime scene with a suspect.