In order to show that you studied this lab carefully, please email me at
eminkoff
 bates.edu
with your NAME and the answers to these 5 questions:
(No need to repeat the questions; the answers alone will do.)
For the first 2 questions, review the meaning of the terms homozygous and heterozygous.
Figure out the genotypes of all parents from the information given, then make a chart of
all possible male and female gametes, as in the example given in the lab. Combine these gametes
in all possible combinations to produce a chart that shows your answer.
(A numerical answer is sufficient; you don't need to send the whole chart.)
- 1. A male fruit fly, heterozygous for both vestigial wings and ebony body, is crossed with a
female homozygous for normal wings and heterozygous for ebony body. What fraction of their offspring
will have normal wings and an ebony body?
- 2. In the same cross as question #1, what fraction of the offspring will have their father's genotype for both traits?
- 3. In pedigrees, individuals are usually specified by using a Roman numeral for their generation in the chart and an Arabic number for their position (reading left to right)
within that generation. In the pedigree that shows cystic fibrosis, if we use the letter c for the allele that causes
the disease, what are the genotypes of individuals III-3 and III-4, the third and fourth individuals shown in generation III (labeled Third Generation)?
- 4. Anastasia was the youngest daughter of Czar Nicholas II of Russia.
She had no known children, and her fate following the Bolshevik Revolution is unknown.
What is the probability that she was a heterozygous carrier of the allele for hemophilia?
- 5. Look carefully at the illustration for gene translation (the last illustration shown for Lab 3). What is the mRNA codon that specifies the tRNA anticodon that inserts the amino acid tyrosine (Tyr)?
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