Biology 3201-2 Test: Genetics
Name:
Answer all questions on this paper. Please read the directions for each section and note
the value of each question (try to do the questions with the highest value first). Scrap
paper will be provided.
Multiple Choice (1 point each) 20 points total
Answer all questions with a letter in the blanks provided to the left of the question.
1. The father of modern genetics:
a. Snook
b. Mendeleve
C. Mendel
c. Mendel
d. Morgan
2. Most of work in genetics should be done with animals or plants with:
a. sexual reproduction
b. short generations
b. short generations
c. asexual reproduction
d. long generations
3. Genetics is the science of:
a. dominance
C. Heredity
b. genes
c. heredity
d. traits
4. Most often _______ traits will be prevalent in a population.
a. dominant
b. sex linked
a. dominant
c. DNA
d. homozygous
5. Homozygous is ______ while heterozygous is _______.
a. good, bad
b. bad, good
c. Pure, hybrid
c. pure, hybrid
d. hybrid, pure
6. Which is not a genetic law? The law of ________
a. dominants Same as the Law of Dominance
b. co-dominants
c. segregation
b. Codominants
d. independent assortment
Biology 3201-2 Test: Genetics
Name:
7. The phenotype ratio for a cross of two pure genes is always:
a. 100%
A. 100% (All
b. 50%
dominant)
c. 25%/75%
d. 75%/25%
8. What is the probability of a couple having 4 daughters in a row?
a. 1/16
a. 1/16 (1/2 x1/2 x 1/2 x 1/2) = 1/16
b. 1/4
c. 1/8
d. 1/32
9. When breeding pure homozygous dominant with pure homozygous recessive in a codominant allele what is the phenotype ratio:
a. 75%/25%
d. 100 % (All heterozygous)
b. 50%
c. 25%/75%
d. 100%
10.Genotype ratio? (for the cross in question 9)
a. 25%/75%
b. 75%/25%
c. 100 % (All heterozygous)
c. 100%
d. 50%
11. Which of the following is a monohybrid?
a. Tt
A. Tt
b.GG
c. gg
d. TT
12. Which of the following is a dihybrid?
a. TTGg
b. TtGG
d. TtGg
c. Ttgg
d. TtGg
13. How can you find out if a plant with a dominant trait is homozygous or
heterozygous?
a. self pollinate
b. cross pollinate
a. Self Pollinate. If the
parent
is Homozygous
c. check seeds
then all offspring produced
d. check leaves
will also be homozygous.
If it is heterozygous, then
both heterozygous and
homozygous offspring will
appear.
Biology 3201-2 Test: Genetics
Name:
14. Which of the following is a sex linked trait?
a. widowos peak
b. hitchhikers thumb
c. Colour blindness is
sex linked. All others are
c. colour blindness
"autosomal" traits.
d. eye colour
15. How are chromosomes mapped in a karyotype?
a. size and weight
b. Size and
b. size and staining
staining.
c. staining and weight
d. weight and length
16. Non-disjunction genetically and biologically is:
a. usually bad
a. Nondisjunction is the failure of chromosomes to separate during
b. good
gamete
formation. This can lead to too many alleles for a trait. Ex: BBb
c. makes no difference
instead of Bb. The Law of Segregation is not kept true.
d. bad
17. Walter Sutton was the first to suggest genes are located in the ________ .
a. sperm
d. Chromosomes.
b. ova
c. a & b
d. chromosomes
18. Two chromosomes that are alike are said to be:
a. homozygous
c. Homologous.
b. heterozygous
Remember, Genes are compared using the terms
c. homologous
Homozygous and Heterozygous
d. linked
19. The following (XX), is the genotype of a _______ .
a. male
b. female
b. Female. A male is XY.
c. neither
20. The idea of gene linkage goes against which of the following laws:
a. dominants
d. Independent assortment. If genes are
b. co-dominants
linked together they are unable to sort
c. segregation
themselves independently of each other.
d. independent assortment
Biology 3201-2 Test: Genetics
Name:
Short Answer (30 points)
1. Describe the difference between genotype and phenotype (5 pts)
Phenotype is the
expression of a trait in an
organism. It is what is
actually seen in an
organism. Genotype is
the actual makeup of
genes of an organism. It
is the actual combination
of alleles.
2. In Chickens, the trait for long toe length is dominant to the gene for Short toe length.
What would be the expected phenotypic and genotypic ratios for a cross between a
Barred Plumage chicken that is heterozygous for long toe length and a white chicken
that has short toes? Show your workings. ( 5 pts.)
Parents: BWLl x WWll
3. There are three genes for blood type in humans: ii (recessive), IB & IA (codominants). Knowing this, find which one of the following offspring is not a child of the
given parents.
Parents:
O type blood (father), AB type blood (mother)
Children:
Barney - type A blood Fred is not a child of this family. Type O blood has ii alleles. Since the mother is
Wilma - type B blood
AB blood, she is incapable of giving the necessary i allele needed to make
Fred's blood type.
Fred- type O blood
Explain why you chose the child you did (remember you may have to testify in court!) (5
pts)
4. Produce the F1 generation for the following pea plants: TTGG X ttgg. Cross the
offspring of F1 to produce F2 and provide phenotype ratios (T=tall, t=short, G=green,
g=yellow) (9 pts)
F1 = All TtGg
F2 generation --> TtGg x TtGg --> Phenotypic Ratio = 9:3:3:1
5. Briefly distinguish between the three Mendelian Laws.(3 pts)
a. Law of dominance : In organisms with contrasting traits, the dominant trait is always
expressed whereas the recessive trait is sometimes expressed.
b. Law of Segregation: During gamete formation, genes(alleles) separate and then
recombine during fertilization.
c. Law of Independent Assortment: Law that states that during gamete formation,
alleles sort themselves independently of each other.