1. Do Now: match the following words with their definitions Genetics Practice

2. Sponge Bob Genetics Review & Questions

3. Genetics Self-Test You have 15 minutes to complete 10 genetics questions which range in difficulty from easy to very hard. The self-test will not be graded, but it will let you know how well you understand the material we’ve been working on for the last week

4. Self-test Results Bear hair Since straight hair is dominant: SS  straight hair Ss  straight hair (heterozygous) Ss  curly hair

5. Bear-hair cross Heterozygous bear on top, curly haired bear on side. Genotype ratio: 1:1 Ss:ss Phenotype ratio: 1:1 straight:curly Ss sSsss sSsss

6. Heterozygous Bear Cross Genotype ratio: 1:2:1 SS:Ss:ss Phenotype ratio 3:1 straight:curly Ss SSSSs s ss

7. Fruit Flies Since white eyes are recessive to red eyes, the white-eyed fly must have the rr genotype. Since the cross produced some white eyed offspring, the red- eyed parent must be a heterozygote. Since the phenotype ratio is 1:1, you should expect an equal number of red-eyed and white-eyed offspring (60) Rr rRrrr rRrrr

8. Two red-eyed flies with white-eyed offspring Since this cross produced white-eyed offspring, both parents must have had a copy of the recessive allele. In other words, they are both heterozygous. Since the phenotype ratio of the cross is 3:1 red:white, we expect there will only be 1/3 as many white eyed flies as red. (10) Rr RRRRr r rr

9. Codominance Since there are 3 phenotypes (red, white, and roan), you immediately know this is codominance or incomplete dominance Since the third phenotype is a result of BOTH alleles being expressed, it must be codiminance. Red x Roan = 50% will be roan RR RRR rRr

10. Roan x Roan 1:2:1 Red:Roan:White Rr RRRRr r rr

11. Morning Glories Since the third phenotype in this example is a blending of the two phenotypes, it is an example of incomplete dominance VV = violet VV’ = light purple V’V’ = white 1:2:1 violet:light purple: white VV’ VVVVV’ V’VV’V’V’

12. Sex-linked heredity When a gene is located on the sex chromosomes, it is said to be a sex-linked trait X + X + normal f X + X o carrier f X o X o color-blind f X + Y normal m X o Y color-blind m 50% of males will be color blind 50% of females will be carriers X+X+ XoXo X+X+ X+X+X+X+ X+XoX+Xo YX+YX+YXoYXoY

13. Rate Yourself Only count a question as right if you got ALL parts right < 6 right = deep trouble 6-7 right = not too good 8 right = on track 9 right = nice 10 right = AWESOME!