When two individuals, both with genotype RrYy are crossed to each other

When two individuals, both with genotype RrYy are crossed to each other, all possible genotypic combinations are produced in the offspring: RRYY, RRYy, RRyy, RrYY, RrYy, Rryy, rrYY, rrYy and rryy. Score each genotype’s phenotype to determine how many visible kinds of offspring‐‐phenotypes—do these 9 genotypes represent?

1. If Morgan crossed a white‐eyed male (Xr Y) with a red‐eyed (normal) female (XR XR), out of 20 offspring how many white‐eyed males will he recover?
2. Which of the following choices would best describe the genotype of a Bb individual?
3. Which of the following crosses will yield at least some homozygous tall pea plants?
4. Mendel’s experimental approach to plant breeding resulted in
5. You have a tall plant pea. Is its genotype TT or Tt? How can we see if a recessive allele (t) is hiding in our tall plant? Several pea plant genotypes are listed below. Which one would be best to cross with your tall pea plant in order to discover its hidden genotype? (Hint: You don’t want to have to look at a lot of offspring to get your answer.) (T? X ??)
6. In pea plants, the allele controlling tallness (T) is completely dominant over its alternative allele controlling shortness (t). Which of the following crosses will yield short (tt) and heterozygous tall (Tt) pea plants in approximately equal numbers?
7. Freckles and red hair are often seen together in humans. It is suspected that the genes for these two traits
8. If two plants with contrasting traits are crossed to each other and one of the traits entirely disappears in the F1 generation, that trait is said to be
9. When male and female flies are crossed to each other, the X chromosome that is in half of the male fly’s sex cells (sperm)
10. Morgan crossed a heterozygous red‐eyed female fly (XWXw) to a red‐eyed male (XWY‐). What was the ratio of different phenotypes for eye‐color in the offspring?
11. In Labrador retriever dogs, B genes control pigment production (BB or Bb gives black, bb gives brown); the E gene controls pigment deposition (EE and Ee give good deposition‐‐black or brown depending on the B genes‐‐and ee gives poor deposition (yellow). A black male Labrador retriever BB Ee is crossed to a yellow female bb ee. What phenotypes will result from this cross and in what frequencies? (BBEe X bbee)
12. In epistasis, the phenotype produced by the alleles of one gene locus
13. In a cross between individuals of genotype TtYy and ttyy, sex cells from the ttyy individual will all have t and y alleles. So they will reveal whatever alleles are present in any sex cell coming from the other parent—whether TY, tY, Ty or ty. So, how many different phenotypes can result from this cross? (TtYy X ttyy)
14. Sickle cell anemia is an extreme example of
15. If two different genes are on the same large chromosome and very far apart then
16. In the phenotype of an individual, a dominant allele
17. In Mendel’s approach to plant breeding he was a(n) ___________; this term indicates that his questions were answered by good observations and experiments.
18. If two genes are linked they will
19. When Morgan crossed a heterozygous red‐eyed female (XRXr) with a red‐eyed male (XRY)
20. In the case of incomplete dominance, the combinations of alleles AA, Aa or aa can result in how many different phenotypes?
21. The karyotype of Drosophila melanogaster contains 4 pairs of homologous ___________.
22. A bb individual is ___________ for a __________ allele.
23. The appearance of a trait is referred to as its
24. In the karyotype of Drosophila melanogaster there is a pair of chromosomes of unequal size. These turned out to be