Problem set 1, Fall 2018student name:
8 points total
Note: Please show your work and define your symbols clearly.
1. You roll a six-sided dice four times.
a) What is the probability of rolling four sixes?
b) What is the probability of rolling no 1’s in four rolls of the dice?
c) What is the probability of rolling at least one 4?
2. You cross AaBbccDdEeFF X aaBbCCDdEeFf. In each case, capital letter denotes dominant, A- gives phenotype A, aa gives phenotype a, and so on.
a) What is the probability of AaBBCcddeeFf offspring?
b) What is the probability of getting offspring with the phenotype AbCDeF?
3. In the plant C. spotrun, blue flowers are recessive to pink flowers and oval petals are recessive to square petals. If a pure-bred plant with blue, square petals is crossed with a plant that's heterozygous for pink, square petals, what are the genotypic and phenotypic ratios of the F1 generation?
4. How is a test cross used to determine the genotype of an organism? If a test cross is performed on a tall plant (tall = dominant) of unknown genotype, what must that plant's genotype be if:
a) half of F1s are tall and half are short?
b) the F1's are all tall?
5. You have discovered a rare, fresh water squid, R. soodae, living in Lake Monroe. Further investigation reveals two true-breeding strains, one with blue spots and short tentacles, and one with yellow spots and long tentacles. In crosses between the two strains, the F1 offspring always exhibit long tentacles and yellow spots. When you cross the F1's, you found 179 with long tentacles and yellow spots, 58 with long tentacles and blue spots, 63 with short tentacles and yellow spots and 20 with short tentacles and blue spots. What are the genotypes of the two original strains? Define your genetic symbols clearly.
6. The state of Indiana participates in a multi-state lottery called Powerball. In powerball, a player chooses 5 numbers from 1 – 49. In addition, a player chooses a single number from 1 – 42, which is called the powerball. The player must match the 5 numbers plus the powerball in order to win the grand prize. What is the probability of winning the grand prize. You must show your calculations (Note: This is an old version of powerball. Odds are lower now).
7. You cross a true breeding red haired, blue eyed purple people eater with one that has green hair and orange eyes (green hair and orange eyes are recessive) to produce doubly heterozygous offspring. You cross the double heterozygous offspring to produce F2 progeny.
a) Please draw a Punnett square showing the genotypes of all of the offpsring.
b) Use a branch diagram to determine the likelihood of getting offspring of the genotype ggOo (where g is the allele that causes green hair when homozygous, o is the allele that causes orange eyes when homozygous).
8. In your studies of the exotic field mouse, Z. crabtreeae, you find that there are two, true breeding strains in the wild. The first strain has red fur, short legs and fuzzy tails, and the second strain has brown fur, long legs and bare tails.
a. To understand the differences between these strains, you cross strain 1 X strain 2. All of the offspring have red hair, long legs and fuzzy tails. You then cross the F1 animals amongst themselves and find the results listed below. Please give the genotypes of each of the F2 phenotypic classes.
425red fur, long legs, fuzzy tails
138 red fur, long legs, bare tails
142red fur, short legs, fuzzy tails
135brown fur, long legs, fuzzy tails
51 red fur, short legs, bare tails
47brown fur, long legs, bare tails
46brown fur, short legs, fuzzy tails
16brown fur, short legs, bare tails
1000
b. What do you expect to see from a test cross involving F2 animals with red fur, short legs and fuzzy tails? Please give the expected genotypes, phenotypes and their relative frequencies.
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