Question

The achoo syndrome (sneezing in response to bright light) and trembling chin (triggered by anxiety) are both dominant traits in humans. a. What is the probability that the first child of parents who are heterozygous for both the achoo gene and trembling chin will have achoo syndrome but lack the trembling chin? b. What is the probability that the first child will not have achoo syndrome or trembling chin?

Answer 1

a. 18.75% (3 of 16)

b. 6.25% (1 of 16)

Step-by-step explanation:

o answer this kind of question you need to make a Punnet square, this kind of diagrams is used to predict the probability of an outspring having a particular genotype. In this case, you need to predict two different traits, I added an image for you to see how this square is done.

First, you need to assign a letter for your traits, I used A for the achoo syndrome and T for the trembling chin, now you need to determine alleles for the parents since both of them are heterozygous both of them will have AaTt (one dominant allele and one recessive allele). Now you are going to take the first allele of you your first trait and combine it with the first allele of your seconds trait (AT), now with the second allele of your second trait (At), now you take the send allele of your first trait and combine it with the first allele of your second trait (aT) and then with the second (at), this is going to be the same for both parents, finally you cross one pair from the mother with one from the father following the order of your square.

Now you'll have 16 combinations, observing them you can find that for your question a. 3 of 16 combinations have at least one dominant allele for achoo syndrome and receive for trembling chin and b. only 1 of 16 with both recessive traits