Download Genetics Unit Practice Test

Name: _________________________________________________________________________________________
Hour: ____________
Genetics Unit Practice Test
Biology B/Genetics Unit
Directions:
 Each question is worth 2 points.
 Take this practice test as though it were a real exam.
1.
Mendel used pea plants to study:
a. Flowering
b. Gamete formation
c. The inheritance of traits
d. Cross-pollination
2.
In a certain species of ant, the gene for long antennae (A) is dominant over the gene for short antennae (a). If
a biologist wants to produce ants with short antennae only, which ants should be crossed?
a. Homozygous long antennae ants with heterozygous long antennae ants
b. Heterozygous long antennae ants with heterozygous long antennae ants
c. Heterozygous long antennae ants with homozygous short antennae ants
d. Homozygous short antennae ants with homozygous short antennae ants
3.
Offspring that result from crosses between homozygous parents with different traits:
a. Are homozygous
b. Make-up the F2 generation
c. Make-up the parental generation
d. Are called hybrids
4.
Which of the following combinations of alleles is homozygous for a trait?
a. Aa
b. BB
c. AO
d. ND
5.
Gregor Mendel concluded that traits are:
a. Not inherited by offspring
b. Inherited through the passing of factors from parents to offspring
c. Determined by dominant factors only
d. Determined by recessive factors only
6.
When Gregor Mendel crossed a tall plant with a short plant, the F 1 plants inherited:
a. An allele for tallness from each parent
b. An allele for tallness from the tall parent and an allele for shortness from the short parent
c. An allele for shortness from each parent
d. An allele from only the tall parent
7.
When Gregor Mendel crossed homozygous tall plants with homozygous short plants, all the offspring were
tall because:
a. The allele for tall plants is recessive
b. The allele for short plants is dominant
c. The allele for tall plants is dominant
d. They were homozygous like their parents
8.
If a pea plant has a recessive allele for green peas, it will produce:
a. Green peas if it also has a dominant allele for yellow peas
b. Both green peas and yellow peas if it also has a dominant allele for yellow peas
c. Green peas if it does not also have a dominant allele for yellow peas
d. Yellow peas if it does not also have a dominant allele for green peas
9.
A tall plant is crossed with a short plant. If the tall F1 pea plants are allowed to self pollinate,
a. The offspring will be of medium height
b. All of the offspring will be tall
c. All of the offspring will be short
d. Some of the offspring will be tall, and some will be short
10. In the P generation, a tall plant was crossed with a short plant. Short plants reappeared in the F 2 generation
because:
a. Some of the F2 plants produced gametes that carried the allele for shortness
b. The allele for shortness is dominant
c. The allele for shortness and the allele for tallness segregated with the F1 plants produced gametes
d. They inherited an allele for shortness from one parent and an allele for tallness from the other parent
11. When you flip a coin, what is the probability that it will come up tails?
a. ½
b. ¼
c. 1/8
d. 1
12. The principles of probability can be used to:
a. Predict the traits of the offspring produced by genetic crosses
b. Determine the actual outcomes of the parents used in genetic crosses
c. Predict the traits of the parents used in genetic crosses
d. Decided which organisms are best used in genetic crosses
13. In the P generation, a tall plant is crossed with a short plant. The probability that an F 2 plant will be tall is:
a. 50%
b. 75%
c. 25%
d. 100%
14. Organisms that have two identical alleles for a particular trait are said to be:
a. Hybrid
b. Homozygous
c. Heterozygous
d. Dominant
15. In the Punnett Square show in the diagram on the previous page, which of the following is true about the
offspring resulting from the cross?
a. About half are expected to be short
b. All are expected to be short
c. About half are expected to be tall
d. All are expected to be tall
16. A punnett square shows all of the following EXCEPT:
a. All possible results of a genetic cross
b. The genotypes of the offspring
c. The alleles in the gametes of each parent
d. The actual results of a genetic cross
17. If you made a punnett square showing Gregor Mendel’s cross between homozygous tall plants and
homozygous short plants, the square would show that the offspring had:
a. The genotype of one of the parents
b. A phenotype that was different from that of both parents
c. A genotype that was different from that of both parents
d. The genotype of both parents
18. Situations in which one allele for a gene is NOT completely dominant over another allele for that gene are
called:
a. Multiple alleles
b. Incomplete dominance
c. Sex-linked traits
d. Multiple genes
19. A cross of a red cow (RR) with a white bull (WW) produce all roan offspring (RW). This type of inheritance is
known as:
a. Incomplete dominance
b. Sex-linked traits
c. Co-dominance
d. Multiple alleles
20. Gregor Mendel’s principles of genetics apply to:
a. Plants only
b. Animals only
c. Pea plants only
d. All organisms
21. Which of the following have been produced by selective breeding?
a. Horse breeds
b. Cat breeds
c. Dog breeds
d. All of the above
22. Which of the following is NOT an example of selective breeding?
a. Allowing only the best milk-producing cows to reproduce
b. Cross disease resistant plants with plants that produce high food yields
c. Mating cats that have long hair with cats that have long tails
d. Allowing dogs to mate only once a year
23. Which of the following includes all the others:
a. Hybridization
b. Inbreeding
c. Selective breeding
d. Induced mutations
From the word bank below, select the term that best fits each description. There is only one correct answer
for each question, and each word may be used only once.
Word Bank:
A. Incomplete Dominance
B. Co-Dominance
D. Multiple Alleles
C. Monohybrid (Single Trait) Cross
E. Sex-Linked Cross
24. A cross involving the ABO human blood groups
25. A cross involving two pink flowers
26. A cross between a cow with a red coat and a cow with a roan coat (roan = red AND white hair)
27. A cross between a tall pea plant (TT) and a short pea plant (tt), which results in 100% tall (Tt) pea plants.
Name: ______________________________________________________________________________________
Hour: _____________
Genetics Practice Test Short Answer Responses
Biology B/Genetics Unit
Directions: Answer the following questions directly onto this paper. Each question is worth 6 points.
1.
A round pea plant (RR) and a wrinkled pea plant (rr) are crossed. Perform the cross below and then answer
the following questions:
a.
What are the percentages of each genotype? _____________________ % RR
_____________________ % Rr
_____________________ % rr
b.
What is the phenotype of each genotype? RR = _________________________________________________
Rr = __________________________________________________
rr = ___________________________________________________
2.
A dark purple flower and a white flower are crossed. Assume that dark purple and white alleles are
incompletely dominant. Perform the cross below and then answer the following questions:
a.
What are the percentages of each genotype?_____________________ % PP
_____________________ % PW
_____________________ % WW
b.
What is the phenotype of each genotype? PP = _________________________________________________
PW = _________________________________________________
WW = _________________________________________________
3.
A red horse and a white horse are crossed. Assume that red and white alleles are co-dominant. Perform the
cross below and then answer the following questions:
a.
What are the percentages of each genotype?_____________________ % RR
_____________________ % RW
_____________________ % WW
b.
What is the phenotype of each genotype? RR = _________________________________________________
RW = _________________________________________________
WW = _________________________________________________
4.
A woman with type A homozygous blood and a man with type AB blood have children. Perform the cross
below and then answer the following questions:
a.
What are the percentages of each genotype?_____________________ % AA
_____________________ % AO
_____________________ % BB
____________________ % BO
___________________ % AB
____________________ % 00
b.
What is/are the genotype(s) of each phenotype? Type A = _________________________________________________
Type B = _________________________________________________
Type AB = _______________________________________________
Type O = _________________________________________________
5.
In the movie Lorenzo’s Oil, the trait for Adrenoleukodystrophy (ALD) is sex-linked and recessive. Only boys
show symptoms of ALD. Girls (or women) do not show symptoms of ALD, but can be carriers of the disorder.
Use the letter A/a to represent the alleles for ALD.
What is the genotype of Lorenzo’s mother Michaela? _______________
What is the genotype of Lorenzo’s father Augusto? _________________
Perform the cross between Michaela and Augusto below AND CIRCLE LORENZO”S GENOTYPE:
6.
Study the following sex-linked recessive pedigree for nearsightedness. Use the letter B/b to complete the
requested genotypes. Note that carriers are NOT symbolized in the pedigree (you need to determine
in an individual is a carrier or not). Each part is worth 2 points
Bob = ______________
Ellen = ______________
Mary = ______________
Barbara = ______________
Alissa = ______________
Mary and Steve are expecting another child. What is the probability that the new baby will be colorblind? __________
What is the relationship between Ellen and Melissa? ______________________________________________________________________
What is the relationship between Steve and Art? ___________________________________________________________________________