Ok so I'm completely frustrated with this Genetics worksheet, I've attempted to do some of the questions but I feel like a frog out of water, any help would be greatly appreciated!
Genetics Problems
In Martian aardvarks, the following traits use the dominant-recessive inheritance pattern:
G = Green skin g = yellow skin
H = horns h = hornless
F = forked tongue f = round tongue
T = sharp teeth t = no teeth
E = two eyes e = cyclops
Monohybrid cross problems
1. Name the genotype of a pure breeding green skinned aardvark.
GG
2. Name the genotype of a pure breeding yellow skinned aardvark.
gg
3. If the pure breeding green skinned aardvark mates with the pure breeding yellow skinned aardvark, what will the expected genotypic and phenotypic ratios of their progeny be?
GGxgg all green-skinned, Gg
4. If two hybrid for skin color aardvarks mate, what will the genotypic and phenotypic ratios of their progeny be?
Gg x Gg genotypes= 1GG:2Gg:1gg and phenotype= 3 green: 1 yellow
5. If an aardvark homozygous dominant for horns mates with a heterozygote and they have 400 babies, how many would be expected to have horns? How many would be expected to be hornless?
HH x Hh 200HH and 200HH= all horned
Dihybrid cross problems
6. If a male aardvark heterozygous for eyes and tongue shape mates with a female that is also heterozygous for both traits, what will the expected phenotypic ratio be for their progeny?
9:3:3:1
7. If two heterozygotes for skin color and teeth mate and have 500 babies, how many would be expected to have sharp teeth and yellow skin? Cross with two alleles involved (not dihybrid)
8. If a male yellow skinned cyclops aardvark mates with a female that is heterozygous for both traits and they have 250 babies, how many would be expected to be yellow skinned and cyclops?
Multiple Alleles
9. If a female that is homozygous for green skin, heterozygous for horns and teeth and homozygous recessive for eyes mates with a male that is homozygous dominant for skin color and heterozygous for all other traits, what will the probabilities be of them producing the following offspring?
a. Green skinned, horned, toothed cyclops
b. Yellow skinned, horned, toothed, cyclops
c. Green skinned, hornless, untoothed, two eyed
d. Green skinned, hornless, toothed, two eyed
e. Green skinned, horned, untoothed, cyclops
10. If a male and a female heterozygous for all traits mate, what will the probabilities of them producing the following offspring be?
a. Green skinned, horned, toothed, cyclops
b. Yellow skinned, horned, toothed, cyclops
c. Green skinned, hornless, untoothed, two eyed
d. Green skinned hornless, toothed, two eyed
e. Green skinned, horned, untoothed, cyclops
f. Yellow skinned, hornless, untoothed, cyclops
Blood Types
11. Give the possible genotypes for the following blood types: A, B, AB, O.
A=AA,AO B=BB,BO AB=AB O=OO
12. Jane has type A blood. Joe has type B blood. Their child has type O blood. Is this possible. Why or why not?
Yes. Genotype of type A can be either AO/AA and the genotype of type B can be either BO/ BB. So if an AO parent and a BO parent have a child, it can be O.
13. Mary has type O blood. Bob has type AB blood. Mary has a child with type O blood. Could Bob be the father of the child? Why or why not?
No, A and B are dominant over O (meaning only the dominant gene is expressed; O type is only expressed when a person has two O alleles).
14. Doug wants to know his genotype concerning his blood type. He knows his blood type is A. His mother had type A blood and his Father had type O blood. What must his genotype be and why?
His blood type is A which means his genotype is AA/AO. There had to be at least 1 A allele for him to have type A which was from his mother.
15. Chandler and Monica have four children. Each child has a different blood type. Chandler is concerned that all four children may not be his. Is it possible for two parents to produce four children each with a different blood type?
Yes, if one parent is type A and the other is type B possibilities are A;AB;O;B.
6. Ralph is in trouble. He is being sued by his former companion for child support. He does not believe that the child is his. He has type B blood. Both of his parents had type AB blood. The child has type O blood. Can this information help him with the problem? Why or why not?
No, the information that is missing is the former companions which contributed to the child’s blood type. The companions blood type is A,B or O.
Multiple Alleles and Incomplete Dominance
In Jovian wombats, there are three alleles for skin color. The SY allele causes yellow skin. The SB allele causes blue skin and the s allele codes for no pigmentation which results in clear skin in the homozygous condition. The wombats with the SY SB genotype have green skin.
17. Give the possible genotypes for the following phenotypes. Green skin, yellow skin, blue skin, clear skin. SySy= yellow skin; SbSb= blue skin; SySb=green skin; ss= clear skin
18. If two green skinned wombats mate and produce 1000 babies, what will the expected number of green, yellow, blue, and clear skinned babies be?
19. If a heterozygous blue skinned wombat mates with a heterozygous yellow skinned wombat, what will the expected phenotypic ratio be for their offspring?
20. Can two wombats produce a litter of wombats with four different phenotypes present? How?
21. Can two clear skinned wombats produce offspring with blue, yellow, or green skin?
22. Can two green skinned wombats produce offspring with clear skin?
23. Can two blue skinned wombats produce offspring with clear skin? Yellow skin? Green skin?
Sex-linked Problems
24. Give the genotypes for the following: normal male, normal female, colorblind male, colorblind female, carrier female. XN XN (female, normal color vision); XN Xn (female, normal color vision, carrier of colorblindness); Xn Xn (female, colorblind); XN Y (male, normal vision) ;Xn Y (male, colorblind)
25. Joe has normal vision but his father was colorblind. Joe's wife has normal vision. Joe is concerned that their children will be colorblind. What is the probability that Joe's children will be colorblind? What is the probability their sons will be colorblind? Their daughters? What is the probability that their daughters will be carriers.
26. Frank has normal vision but his wife is colorblind. What is the probability that their sons will be normal?
What is the probability their sons will be colorblind? What is the probability their daughters will be colorblind?
What is the probability their daughters will be carriers. What is the probability their daughters will be normal?
27. Can a normal male produce a daughter that is colorblind?
28. Can a normal male produce a son that is colorblind?
29. How could a colorblind female be produced?
Quick Reply
