298,253 views
12 votes
12 votes
For each of the four traits, decide which of the possible genotype crosses could represent the family you studied. For example, if both parents express the dominant trait, and only two of three children express the dominant trait, then the parents must be Aa and Aa. Otherwise, if the parents were (AA and Aa) or (AA and AA), all of the children would express the dominant trait. Only the AaxAa table is consistent with two dominant phenotype parents having children that are both dominant and recessive phenotypes.Remember that in each case, the capitalized phenotype (T, H, B, E) represents expression of the dominant gene, and the lower-case phenotype (t, h, b, e) represents expression the recessive gene. Remember also that the phenotype T could be produced by the genotype TT or the genotype Tt, while the phenotype t can only be produced by the genotype tt.Submit your conclusions about the genotypes of the parents for each of the four traits, and an explanation of how your data supports your conclusions. Use paragraphs with complete sentences and proper English grammar.That's the chart of my family and their traits persontongue testhair testeyes test ear testFather t H B eMother T H B EChild 1 t H B EChild 2 T H B eChild 3 T H B e And here's some helps and hintsFor the Tongue test, the three genotypes would be TT, Tt, and tt. That means the unique crosses are:TT x TTTT x TtTT x ttTt x TtTt x tttt x ttNow that you have a list of all possible crosses, it is time to start eliminating ones that are not possible (do not agree with your Part 1 data)....Start with the parents phenotypes:(Remember, the dominant phenotype, T, means the genotype could be either TT, or Tt.... The recessive phenotype, t, means the genotype is tt.)What is the father's phenotype?What are the possible genotype(s) for that phenotype?What is the mother's phenotype?What are the possible genotype(s) for that phenotype?Now, look at the six possible crosses. Eliminate any where the genotypes disagree with the possible genotypes you just listed above....Next, look at the offspring/children:Which of the following accurately describes the offspring/children?All have the dominant phenotype.All have the recessive phenotype.Some have the dominant phenotype, and others the recessive phenotype.Finally, look at the Punnett squares for each of the crosses that you were unable to eliminate using the parent's phenotypes..Eliminate any that have a 0% probability/probability of matching the children/offspring phenotypes.....What remains will be a list of crosses that agree with each parent's phenotype, and that also have some possibility of matching each offspring/children phenotype, too.List those crosses. Then, for each, explain how it is a possible match.Once you finish with the Tongue test, do the same for each of the other traits, too.

For each of the four traits, decide which of the possible genotype crosses could represent-example-1
User Michael Rogers
by
2.6k points

1 Answer

23 votes
23 votes

Here they are telling us the phenotypes of a family for four traits, with the alleles represented by the letters in brackets:

• Tongue (T/t)

,

• Hair (H/h)

,

• Eyes (B/b)

• Ear (E/e)

The capital letters represent de dominant allele, and the lower case represents the recessive allele.

They are giving us the following phenotypes for a family and asking us to determine the parent's genotype:

• Father: t H B e

,

• Mother: T H B E

,

• Child 1: t H B E

,

• Child 2: T H B e

,

• Child 3: T H B e

We can start with the recessive phenotype because we know for sure that they are recessive homozygous, which means they have two copies of the recessive gene.

• Father: ,tt, H B ,ee

,

• Mother: T H B E

,

• Child 1: ,tt, H B E

,

• Child 2: T H B ,ee

,

• Child 3: T H B ,ee

User LordDave
by
2.8k points
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.