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A scientist studying Drosophila received three different mutants that all had tiny wings. When flies with the r1 mutation were crossed with flies with the r2 mutation, all offspring had wild-type wing size. When flies with the r1 mutation were crossed with flies with the r3 mutation, all offspring had wild-type wing size. What wing size would you expect if the scientist crossed flies with the r2 mutation with flies with the r3 mutation, and why?

Which of the following statements are TRUE about meiosis I? Select all that apply.

How many chromatids are present in a single cell at the end of anaphase II in a diploid organism with n = 8 chromosomes in its gametes?

In wasps, females are diploid and males are haploid. In one species, 2N = 44. How many chromosomes would a male stingless bee of this species have?

In a species of bird, feather color is an autosomal trait that shows complete dominance. Yellow feathers and pink feathers are the two phenotypes observed. Field surveys show that most birds in the population have yellow feathers. Based on this information alone, the more common feather color must be coded for by the:

Same genetic system as above (M recessively epistatic to P). What proportion of offspring will have white coloration from the following cross: PpMm × ppmm (uppercase P lowercase p uppercase M lowercase m crossed with lowercase p lowercase p lowercase m lowercase m)

What is the probability that both individuals IV-1 and IV-2 will be affected?

In another species, individuals with one X chromosome show increased transcriptional activity from that X chromosome compared to the transcriptional activity of each X chromosome in individuals with two X chromosomes. Which dosage compensation mechanism is occurring?

In a species of lizard, skin color is determined by a single gene with two alleles. A lizard from a true-breeding green strain is mated with a lizard from a true-breeding brown strain. The F1 offspring are all green. Two of the F1 offspring are mated with each other. What proportion of the green F2 offspring is expected to be homozygous?

If an affected father and an unaffected mother have children such that all daughters but no sons show a rare disease, what type of inheritance pattern does this suggest?