Download Genetics Test Review Sheet

Name: ________________________
5.2 and 5.3 Test Review Sheet-PAP
1. Two parents with the genotype Ss for a genetic disorder caused by a
recessive allele are crossed. What would the genotype for the genetic
disorder be? Show the Punnett square and give the phenotypic ratio.
S
s
S
SS
s
Ss
Ss
ss
2. Show the cross for a genetic disorder caused by a dominant allele
between two heterozygous parents. Will any of their children inherit
this disorder?
G
g
G
GG
Gg
g
Gg
gg
3. Using letter R, create the following.
Homozygous dominant: ________
Homozygous recessive: ___________
Heterozygous:__________________
4. Why is a Punnett Square useful?
5. Describe each of Mendel’s two laws.
a. Law of Independent Assortment:
b. Law of Segregation:
6. What is genotype?
7. What is phenotype?
8. What is a trait?
9. Why might a recessive allele not be expressed (not show up)?
10. In order to show the phenotype of a disorder caused by a recessive
allele, what must the genotype be?
11. What must a female’s genotype be if she shows the phenotype for a sexlinked trait?
12. What does crossing over result in?
13. What is co-dominance?
14. How does the phenotype appear when co-dominant alleles are present?
15. What is incomplete dominance?
16. How does the phenotype appear when incompletely dominant alleles are
present?
17. What are sex-linked traits?
18. Give three examples of sex-linked traits.
19. What type of alleles cause most human genetic disorders: dominant or
recessive?
20. What type of gene is Huntington’s disease caused by: dominant or
recessive?
21. If tall (T) is dominant over short (t), complete the following:
Write the Genotypes:
Homozygous Dominant = _____
Homozygous Recessive = _____
Heterozygous = _____
22. If black fur (B) is dominant over white fur (b), complete the following
Write the Phenotypes:
BB = _____________
Bb = __________________
bb = ___________________
23. Define the following:
a. Dihybrid:
b. Heredity:
c. Haploid:
24. What does true-breeding mean?
25. What happened when Mendel crossed true-breeding tall plants with truebreeding short plants?
26. What are the possible allele combinations with a genotype of TtAA?
27. What is Mendel’s principle of dominance mean?
28. What is homozygous?
29. What is heterozygous?
30. What ratio of phenotypes would result with the cross of two hybrids for
two different traits?
31. Show the genotypes of the parents for the following: in pea plants
tallness is dominant over short, white flowers if dominant over purple.
What would the genotypes of a heterozygous purple flowered pea plant
and a short heterozygous white plant look like?
32. How many copies of the recessive allele is needed for an organism to
show the trait in its phenotype?
33. What is a karyotype?
34. What is the probability that a human offspring will be male?
35. What genotype represents a human female? Male?
36. What does it mean when a characteristic has multiple alleles?
37. What does it mean when a characteristic is polygenic?
38. What would the following Karyotypes mutation be called?
39. Gray feathers are dominant over white in turkeys. Fill in the allele
combinations for each turkey in the cross below. You will need to determine
the CORRECT letter to represent the alleles (complete the key first):
Gray =
White =
X
______
______
Use complete sentences to answer the following:
a) Is the white turkey in the P generation heterozygous or homozygous?
How do you know?
_______________________________________________________
_______________________________________________________
____________________________
b) Is the gray turkey in the P generation heterozygous or homozygous?
How do you know?
_______________________________________________________
_______________________________________________________
_________________________
c) If the gray turkey in the P generation was homozygous, what would
you expect the offspring to look like?
____________________________________________________
____________________________________________________
40.In rabbits, grey hair is dominant to white hair. Also in rabbits, black eyes
are dominant to red eyes.
GG = gray hair
Gg = gray hair
gg = white hair
BB = black eyes
Bb = black eyes
bb = red eyes
What are the phenotypes (descriptions) of rabbits that have the following
genotypes:
Ggbb ____________________ ggBB ________________________
ggbb ____________________ GgBb _________________________
A male rabbit with the genotype GgBb is crossed with a female rabbit with
the genotype GgBb The square is set up below. Fill it out and determine the
phenotypes and proportions in the off spring.
How many out of 16 have grey fur and black eyes? ____
How many out of 16 have grey fur and red eyes? _____
How many out of 16 have white fur and black eyes? ____
How many out of 16 have white fur and red eyes? ____