Download GENETICS EXAM STUDY GUIDE 1. Tongue rolling (R) is dominant

GENETICS EXAM STUDY GUIDE
1. Tongue rolling (R) is dominant over non-tongue rolling (r). If a person cannot roll their tongue, what
would be his/her genotype? _____
Round seed pods are dominant over wrinkled seed pods. The Punnett square below shows a cross
between parents with round and wrinkled seed pods. Use the following diagram to answer the next
four questions.
2. What is the phenotype of the offspring in block A? ________________
3. What is the genotype of the wrinkled parent? ____________________
4. What is the genotype of the offspring in blocks B and D? _____________
5. What is the phenotype of the offspring in block C? ________________
6. In 1910, Thomas Morgan discovered traits linked to sex chromosomes in fruit fly. The Punnett square
below shows the cross between red-eyed females and white-eyed males. Fruit flies usually have red
eyes. If a female and male offspring from the cross shown below are allowed to mate, complete the
blank punnett square and list the genotypes and phenotypes of these F2 generation offspring. (see
figure)
__________________________________________________________________________________
7. Which genotype illustrates codominance of alleles that control blood type in humans?_________
8. What conclusion about the F1 genotype can be drawn from the genetic information
above?____________________________________________
9. In pea plants, purple flowers are dominant to white flowers. If two heterozygous purple plants are
crossed, what percent of the offspring will probably be white? ________
10. In cats, gene E produces yellow fur and gene B produces black fur. A cat that inherits both of these
genes has patches of yellow and black fur and is known as a calico. The alleles for black or yellow are
located on the X-chromosome. Calico coat color is most likely due to what type of special inheritance?
11. Complete the Punnett square below for a cross of cats.
12. What is the phenotype of the male cat? _______________
13. What is the phenotype of the female cat? _______________
14. List what the offspring look like. ________________________________________________________
15. Forms of the same gene with different phenotypic expressions are called ____________.
16. In corn plants, green (G) is dominant to albino (g). What is the chance of a heterozygous cross
producing albino corn plants? ____________
17. If a man who has type O blood marries a woman who has type AB blood, what genotypes and
phenotypes could we see in their offspring? Show your work using the punnett below.
18. When using Punnett squares to show inherited probability, a capital letter stands for the
________________ allele.
Using the genetic pedigree above, answer the following questions.
19. Person #4 represents _______________________________________.
20. Person #3 represents a _____________________________________.
21. Person #1 had to be _______________________.
22. A red petunia and a white petunia are crossed. If red and white alleles show incomplete dominance,
what color will the offspring be? _______________________
23. In a Mendelian Cross of purebred dominant and purebred recessive, the percentage of offspring with a
dominant phenotype in the F1 generation is __________.
24. A color-blind woman marries a man who has normal color vision. What are their chances of having a
color-blind daughter? Show your work using the punnett below.
25. A genetic pedigree showing that only males are affected by a certain disorder is evidence of what type
of inheritance? _____________
26. In mice, the gray fur gene (G) is dominant and the gene for black fur (g) is recessive. If 50% of a mouse
litter is black, what parental cross probably produced this result? _____X_____
27. Mendel’s early work with pea plants demonstrated a significant genetic discovery. The crossing of
homozygous tall pea plants with homozygous short pea plants always resulted in tall plants and
demonstrated that tallness in pea plants is a trait that is _______________.
28. What is the chance that the child of two individuals, one heterozygous with Type A blood, and the other
heterozygous with Type B blood, will have Type O blood? _______________
29. An organism in which two alleles for a trait are different is _________________.
30. When purebred tall plants are crossed with hybrid tall plants, the offspring would be
_______________________________________________________________________________
31. Traits that are found on the X chromosome are said to be _____-___________.
32. The actual genetic makeup of an organism is called its _________________.
33. What an organism looks like is referred to as its _______________.
34. In a Mendel’s experiment, the monohybrid cross of the short and tall plants in the Pl generation resulted
in 100 % heterozygous plants in the Fl generation. What was the phenotypic ratio of the F2
generation?_________________________
35. Complete the Punnett Squares below and answer the following questions.
In Hobbits, hairy feet are dominant over hairless feet.
F1 generation: cross 1
homozygous dominant
with a homozygous
recessive
F2 generation: cross 2
of the offspring of the
F1 generation
36. In the first generation, what portion of the Hobbits has hairless feet? ___________
37. In the first generation, what portion of the Hobbits has hairy feet? ___________
38. In the second generation, what portion of the Hobbits is purebred? ____________
39. In the second generation, what portion of the Hobbits has hairless feet? ____________
40. What are the genotypes that you would have to cross to get Hobbit offspring with 50% hairy feet and
50% hairless feet? _______ X ______