Genetics Review Questions

A. Genetic Crosses 1. a. symbols for the two alleles you have for a trait (AA) b. the way you look because of the alleles you have for a trait c. When you have the same 2 alleles for a trait (AA or aa) d. When you have 2 different alleles for a trait (Aa) e. The allele that shows in a heterozygote (ie. A in Aa) f. Only shows when you have both alleles (a in aa) g. The passing of traits from one generation to the next h. A cross for one trait i. A cross for 2 traits j. Square to show the possible genotypes of the offspring of a given cross k. The “flavor” of a gene. Ie. Red allele for hair color gene l. Parent generation, offspring, offspring of the cross of offspring m. heterozygous

A. Genetic Crosses 2. Law of independent assortment: Just because you get your mom’s hair color, you won’t necessarily get her ear shape. (This is only true when the genes are on different chromosomes)

A. Genetic Crosses 3. a.W is dominant; w is recessive b. WW ww c.White brown d.Punnet square: e.Ww (genotype) White (phenotype) WW wWw w Ww WWWWw w ww f. g. WW = white Ww = white ww= brown h. ¾ = 25% i. ¼ = 75% j. 2 (because ¼ of 8 = 2)

A. Genetic Crosses 5. It is homozygous recessive 6. 9:3:3:1 9 show both dominant phenotypes 3 show A and b 3 show a and B 1 shows all recessive

B. Meiosis 1. a.1 of each type of chromosome b.2 copies of each chromosome, 1 from mom, 1 from dad c.Sex cells produced by meiosis (1n) d.Sperm (n) and egg (n) join to form a zygote (2n) e.Body cells (2n) f.Two chromosomes with the same genes but different alleles- 1 from mom and 1 from dad g.When parts of homologous chromosomes break off and rejoin to the other homologous chromosome so that the chromosome may have different alleles than before. This increases genetic variation

B. Meiosis 2. Somatic (body cells) 3. Gametes (sex cells) 4. Sister chromatids 5. Homologous chromosomes 6. Sister chromatids 7. 2 diploid (2n) 8. 4 haploid (n) 9. Diploid (2n) 10. Crossing over. Increases genetic variation (2n) 6= n 12. True 13. true