This pedigree shows the inheritance pattern of a recessive
maternal effect gene in Drosophila. In maternal effect,
the offspring’s phenotype is under the control of nuclear gene
products present in the mother's egg. In this example, the presence
of the a + allele in the mother is required for
proper wing development in the offspring.
In the pedigree, individuals who are wingless are indicated by a
shaded symbol. The phenotypes and genotypes are only provided for
the first generation (individuals 1 and 2)
What are all the possible genotypes for individual 1's
Select all that apply.
a +/a +
This gene is a recessive maternal effect gene. Since the
presence of nuclear gene products in the mother's egg, dictates the
phenotype, and individual 1 has normal wing development, Individual
1's mother had Wild Type copy of the allele(a+). However, since
Individual 1 is homozygous recessive for this gene, and one of
these alleles came from it's mother, Individual 1's mother also had
the Mutant Allele.
Therefore, the only possible genotype for Individual 1's mother