GENETICS AND INHERITANCE LAB

Part I Allele(s) from Mother Allele(s) from Father Genotype Phenotype Sex of child:    Tails   Boy Face shape R r Rr Round Chin Shape (I) V v Vv Very Prominent Chin Shape (II) r R rR Round  Cleft chin A A AA Absent Skin color Abcd abCd AabbcCdd Very Light Brown Hair type C c Cc Wavy Widow’s Peak w w ww Absent Eyebrows (I) B B BB Bushy Eyebrows (II) N n Nn Not Connected Eyebrow color H h Hh Red Eyes distance apart E E EE Close Together Eyes size e E eE Medium Eyes shape a A aA Almond (wide) Eyes slant h h hh Upward slant Eyelashes l l ll Short Eye color aAa AAA aAAAaA Light Brown Mouth size m m mm Narrow  Lips L L LL Large Protruding lower lip H H HH Protruding lower Lip Dimples d D dD Present Nose size n n nn Small Nose shape r R rR Rounded Nostril shape R R RR Rounded Earlobe Attachment f F fF Free Freckles on checks F F FF Present Hair color H h Hh Red
Part II      Genetic Problem I: For each of the diploid genotypes presented below, determine the genetic make up for all of the possible gametes that would result through the process of meiosis. Remember, each egg or sperm must have one of each letter. That letter can be upper or lower case.   A) Rr Answer = Rr r R Rr Rr Rr Rr B) RrYy Answer = RY, Ry, rY, ry Y y R RY Ry r rY ry C) rrYy Answer = rY, ry, rY, ry Y y r rY ry r rY ry D) RrYY Answer = RY,RY,rY,ry Y Y R RY RY r rY rY 2   For each of the following, state whether the genotype of a diploid or haploid cell is represented. A) Haploid B) Diploid C) Haploid D) Diploid
3     Yellow guinea pigs crossed with white ones always produce cream colored offspring. Two cream colored  guinea pigs when crossed produced yellow, cream and white offspring in the ratio of l yellow: 2 cream: l  white. Explain how these colors are inherited. No calculations needed! Name the type of inheritance this  represents.   The type of inheritance this represents is incomplete dominance. The colors are inherited because each guinea pig inherits 2 genes fro each trait from their parent.
4      In sheep, white is due to a dominant gene (B), black to its recessive allele (b). A white ewe mated to a  white ram produces a black lamb. What are the genotypes of the parents? You might need to construct  Punnet squares experimenting with different crosses to come up with this answer. Name the type of   inheritance this represents.  The genotypes of the parents are Bb,BB,bb. The type of inheritance this represents is Dominant.  B b B BB Bb b bB bb
5     In peas, yellow color (G) is dominant to green color (g). A heterozygous yellow is crossed with a green.  What is the expected phenotype ratio of the offspring? Name the type of inheritance this represents.  The type of inheritance this represents is Dominant. The expected phenotype ratio of the offspring is 3:1 (75% will be green and 25% will be yellow) G g G GG Gg g gG gg
6     White color (Y) is dominant to yellow color (y) in squash. A heterozygous white fruit plant is crossed with   a yellow fruit plant. What is the expected phenotype ratio of the offspring?  What is this type of inheritance called? This type of inheritance is dominant-recessive.  The expect phenotype ratio of the offspring is 3:1. Y y Y YY Yy y yY yy
7      In certain flowers, a cross between homozygous red and a homozygous white will always result in a pink     flower. A cross is made between two pink flowers. What is the predicted phenotype ratio of the colors red, pink and white appearing in the offspring?  What is this type of inheritance called?          This type of inheritance is called incomplete dominance.  R R Y R Y YR YR Y YY YR Y YR YR Y YY YR