Name: __________________________________ Date: _______________ Period: _______
Genetics Biology Test
Directions: Circle the one best answer choice for each question.
1. Who is known as the father of genetics?
a. Darwin
b. Hooke
c. Watson and Crick
d. Mendel
2. Which pattern of inheritance produces an offspring that expresses both phenotypes?
a. simple dominance
c. co-dominance
b. sex-linked
d. incomplete dominance
3. Which pattern of inheritance produces an offspring that expresses a blending of both phenotypes?
a. simple dominance
c. co-dominance
b. sex-linked
d. incomplete dominance
4. The combination of alleles that an individual inherits is called the ___
a. genotype
b. trait
c. phenotype
d. zygote
e. gamete
5. Recessive alleles may not be expressed because they are
a. masked by a dominant allele.
c. the most common allele in a population.
b. the least common allele in a population.
d. there is no such thing as a recessive trait.
6. Which of the following statements is true of heterozygous alleles?
a. They cannot ever produce homozygous offspring
b. They are identical genes at the same locus on sister chromatids.
c. They are different forms (alleles) of the same gene on homologous chromosomes.
d. They are more likely than homozygous alleles to cross over.
7. In a genotype for plant height, such as Tt, what does each letter represent?
a. one genome
c. one allele
e. mitosis
b. one gene
d. one gamete
8. The Human Genome Project was begun in 1988 by scientists from 13 nations as a worldwide effort to understand
the sequencing of all of the DNA in the human body. What is one potential scientific benefit of this research?
a. It will create communication between research centers.
b. It will help to explain human cultural differences.
c. It helps to classify man most accurately in the animal kingdom.
d. It will help find the genes responsible for many diseases
9. When is a recessive allele expressed in offspring?
a. when two copies are present
b. when both parents have a dominant allele
c. when the offspring is heterozygous (simple dominance)
d. when the offspring show the dominant trait
10. If an individual receives two alleles that are different for a trait, the individual is ____
a. dominant
c. heterozygous
e. co-dominant
b. recessive
d. homozygous
Black fur (B) is dominant to brown fur (b)
Complete the Punnett Square:
B
Bb
11. What are the genotypes of the parents?
12. What are the phenotypes of the parents?
b
13. List all offspring genotype possibilities and provide a phenotype for each genotype:
14. What is the genotype ratio?
15. What percent of the offspring will have black fur?
16. What percent of the offspring will have brown fur?
17. What is the phenotype ratio?
Black fur (B) is dominant to brown fur (b)
Create a cross of two heterozygous parents:
18. What is the genotype of the parents?
19. What is the phenotype of the parents?
20. List all offspring genotype possibilities and
provide a phenotype for each genotype:
21. What is the genotype ratio?
22. What percent of the offspring will have black fur?
Bb
23. What percent of the offspring will have brown fur?
24. What is the phenotype ratio?
Black fur (B) is codominant to white fur (W)
Create a cross of a heterozygous parent and a black parent:
25. What are the genotypes of the parents?
26. What are the phenotypes of the parents?
27. List all offspring genotype possibilities and provide
a phenotype for each genotype:
28. What is the genotype ratio?
29. What percent of the offspring will have black fur?
30. What percent of the offspring will have white fur?
31. What percent of the offspring will have black and white spotted fur?
32. What is the phenotype ratio?
Black fur (B) is incomplete dominant to white fur (W)
Create a cross of two heterozygous parents:
33. What is the genotype of the parents?
34. What is the phenotype of the parents?
35. List all offspring genotype possibilities and provide a phenotype for each genotype:
36. What is the genotype ratio?
37. What percent of the offspring will have black fur?
38. What percent of the offspring will have white fur?
39. What percent of the offspring will have grey fur?
40. What is the phenotype ratio?
In pea plants, tall (T) is dominant to short (t) and yellow seeds (G) is dominant to green seeds (g). Use
the Punnett square below to answer the following questions.
TG
Tg
tG
tg
TG
TTGG
TTGg
TtGG
TtGg
Tg
TTGg
TTgg
TtGg
Ttgg
tG
TtGG
TtGg
ttGg
ttGg
tg
TtGg
Ttgg
ttGg
ttgg
41. What is the probability that there will be an offspring that is tall with green seeds?
42. What is the probability that there will be an offspring heterozygous for both traits?
In Humans, Type A blood (IA) is codominant with Type B blood (IB) and Type O blood (Ii) is recessive.
Complete the following Punnett Square for a Type O mother and a Type AB father.
43. What is the probability that they will have a Type O baby?
44. Examine the pedigree above. Is this a dominant or recessive trait?
45. Fill out the blanks of the pedigree above using AA, Aa, or aa
46. How many children does the original couple have?
47. How many grandchildren does the original couple have?
48. What is the sex of the grandchild?
49. How many individual have the trait?