Sponge Bob Genetics Assignment Study Guide

Bikini Bottom Genetics Scientists at Bikini Bottoms have been investigating the genetic makeup of the organisms in this community. Use the information provided and your knowledge of genetics to answer each question. 1. For each genotype below, indicate whether it is a heterozygous (He) OR homozygous (Ho). TT: Ho Bb: He DD: Ho Ff: He tt: Ho dd: Ho Dd: He ff: Ho Tt: He bb: Ho BB: Ho FF: Ho Which of the genotypes in #1 would be considered purebred? TT, DD, tt, dd, ff, bb, BB, FF Which of the genotypes in #1 would be hybrids? Bb, Ff, Dd, Tt 2. Determine the phenotype for each genotype using the information provided about SpongeBob. Yellow body color is dominant to blue. YY: Yellow body Yy: Yellow body yy: blue body Square shape is dominant to round. SS: Square shape round shape Ss: ss: 3. For each phenotype, give the genotypes that are possible for Patrick. A tall head (T) is dominant to short (t). Tall: TT or Tt Short: tt Pink body color (P) is dominant to yellow (p). Pink body: PP or Pp Yellow body: pp 4. SpongeBob SquarePants recently met SpongeSusie Roundpants at a dance. SpongeBob is heterozygous for his square shape, but SpongeSusie is round. Create a Punnett square to show the possibilities that would result if SpongeBob and SpongeSusie had children. HINT: Read question #2! S s A. List the possible genotypes and phenotypes for their children. Ss ss SS: Square shape Ss: Square shape, ss: round shape s Ss ss B. What are the chances of a child with a square shape? 2 out of 4 or 50 % s C. What are the chances of a child with a round shape? 2 out of 4 or 50 % 5. Patrick met Patti at the dance. Both of them are heterozygous for their pink body color, which is dominant over a yellow body color. Create a Punnett square to show the possibilities that would result if Patrick and Patti had children. HINT: Read question #3! P PP: pinkPPbody P Pp p Pp pp A. List the possible genotypes and phenotypes for their children. Pp: pink body pp: yellow yellow B. What are the chances of a child with a pink body? 3 out of 4 or 75 % p C. What are the chances of a child with a yellow body? 1 out of 4 or 25 % 6. True or false? Dominant alleles (traits) are more common in the population than recessive alleles (traits). FALSE. 7. True or false? Dominant alleles (traits) are “healthier” traits than recessive traits. FALSE. 8. If a purebred black chicken was bred with a purebred white chicken, what would the offspring look like if these traits displayed incomplete dominance? Black and White 9. If a purebred black chicken was bred with a purebred white chicken, what would the offspring look like if these traits displayed codominance? GREY. 10. Provide some examples of traits that display polygenic (many genes) inheritance. Height, skin color, eye color, hair color, body shape, weight. 11. Some characters have more than two choices (= multiple alleles). Human blood type is one example. There are four ABO human blood types. List the four human ABO blood types below. A, B , AB , and O . 12. Everyone in Squidward’s family has light blue skin, which is the dominant trait for body color in his hometown of Squid Valley. His family brags that they are a “purebred” line. He recently married a nice girl who has light green skin, which is a recessive trait. Create a Punnett square to show the possibilities that would result if Squidward and his new bride had children. Use B to represent the dominant gene and b to represent the recessive gene. B B A. List the possible genotypes and phenotypes for their children. Bb Bb Bb: Light blue skin b Bb Bb B. What are the chances of a child with light blue skin? 100 % b C. What are the chances of a child with light green skin? 0 % D. Would Squidward’s children still be considered purebreds? Explain! ANS: NO, they will not be considered purebreds instead hybrids because they possess both dominant and recessive character (HETEROZYGOUS). 13. Assume that one of Squidward’s sons, who is heterozygous for the light blue body color, married a girl that was also heterozygous. Create a Punnett square to show the possibilities that would result if they had children. B b E. List the possible genotypes and phenotypes for their children. BB Bb BB: Blue body Bb: light blue body bb: green body B Bb bb b F. What are the chances of a child with light blue skin? 75 % G. What are the chances of a child with light green skin? 25 % 14. Mr. Krabbs and his wife recently had a Lil’ Krabby, but it has not been a happy occasion for them. Mrs. Krabbs has been upset since she first saw her new baby who had short eyeballs. She claims that the hospital goofed and mixed up her baby with someone else’s baby. Mr. Krabbs is homozygous for his tall eyeballs, while his wife is heterozygous for her tall eyeballs. Some members of her family have short eyes, which is the recessive trait. Create a Punnett square using T for the dominant gene and t for the recessive one. T t E. TT the Ttsible genotypes and phenotypes for their children. TT: tall eyeballs Tt: tall eyeballs T TT Tt T F. Did the hospital make a mistake? Explain your answer! ANS: Yes, they did make a mistake, because their genetic crossing shows that it is not possible to have short eyeballs.