Bikini Bottom Genetics 2

Bikini Bottom Genetics 2 Name __________________________ Use your knowledge of genetics to complete this worksheet. 1. Use the information for SpongeBob’s traits to write the phenotype (physical appearance) for each item. Trait Body Shape Body Color Eye Shape Nose Style Dominant Gene Squarepants (S) Yellow (Y) Round (R) Long (L) Recessive Gene Roundpants (s) Blue (y) Oval (r) Stubby (l) (a) LL-______________ (e) Rr-_______________ (b) yy-_______________ (f) ll- _______________ (c) Ss-_______________ (g) ss- _______________ (d) RR - _____________ (h) Yy -______________ 2. Use the information in the chart in #1 to write the genotype (or genotypes) for each trait below. (a) Yellow body - ___________ (e) Stubby nose - ___________ (b) Roundpants - ___________ (f) Round eyes - ____________ (c) Oval eyes - ______________ (g) Squarepants - ___________ (d) Long nose - _____________ (h) Blue body - ____________ 3. Determine the genotypes for each using the information in the chart in #1. (a) Heterozygous round eyes -_____ (c) Homozygous long nose - ______ (b) Purebred squarepants - ______ (d) Hybrid yellow body - ______ 4. One of SpongeBob’s cousins, SpongeBillyBob, recently met a cute squarepants gal, SpongeGerdy, at a local dance and fell in love. Use your knowledge of genetics to answer the questions below. (a) If SpongeGerdy’s father is a heterozygous squarepants and her mother is a roundpants, what is her genotype? Complete the first Punnett square to show the possible genotypes. Based on your results, what would Gerdy’s genotype have to be? _________ (b) Complete the second Punnett square to show the possibilities that would result if Billy Bob & Gerdy had children. NOTE: SpongeBillyBob is heterozygous for his squarepantsshape. (c) What is the probability of kids with squarepants? _____ % (d) What is the probability of kids with roundpants? _____ % 5. SpongeBob’s aunt and uncle, SpongeWilma and SpongeWilbur, have the biggest round eyes in the family. Wilma is believed to be heterozygous for her round eye shape, while Wilbur’s family brags that they are a pure line. Complete the Punnett square to show the possibilities that would result if SpongeWilma and SpongeWilbur had children. (a) Give the genotype for each person. Wilma - _______ Wilbur - ________ (b) Complete the Punnett square to show the possibilities that would result if they had children. (c) What is the probability that the kids would have round eyes? ____ % (d) What is the probability that the kids would be oval eyes? ____ % 6. SpongeBob’s mother is so proud of her son and his new wife, SpongeSusie, as they are expecting a little sponge. She knows that they have a 50% chance of having a little roundpants, but is also hoping the new arrival will be blue (a recessive trait) like SpongeSusie and many members of her family. If SpongeBob is heterozygous for his yellow body color, what are the chances that the baby sponge will be blue? Use the Punnett square to help you answer this question. 7. SpongeBob’s aunt is famous around town for her itty, bitty stubby nose! She recently met a cute squarepants fellow who also has a stubby nose, which is a recessive trait. Would it be possible for them to have a child with a regular long nose? Why or why not? Use the Punnett square to help you answer this question. 8. If SpongeBob’s aunt described in #7 wanted children with long noses, what type of fellow would she need to marry in order to give her the best chances? Use the Punnett square to help you answer this question. Bikini Bottom Genetics 2 Answer Key: 1. A - long nose, B - blue body, C - squarepants, D - round eyes, E - round eyes, F - stubby nose, G roundpants, h - yellow body 2. A - Yy & YY, B - ss, C - rr, D - LL & Ll, E - ll, F - RR & Rr, G - SS & Ss, H - yy 3. A - Rr, B - SS, C - LL, D - Yy 4A - See square at right, Gerdy’s genotype = Ss, 4B - BillyBob’s genotype = Ss 4C - SS & Ss = squarepants and ss = roundpants 4D - 75% 4E - 25% 5A - Wilma = Rr, Wilbur = RR 5B - See square at right 5C - RR & Rr = round eyes 5D - 100% 5E - 0% 6. The Punnett square shows that they would have a 50% chance (2 out of 4) for a little sponge with a blue body color. 7. Since both people are recessive, the Punnett square shows that they have 0% chance for a child with a long nose. 8. SpongeBob’s aunt would have to marry a purebred long nosed man (LL) in order to have the best chances for long-nosed children.