SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
For Teacher use:
Knowledge/Understanding Thinking/Investigation Communication
/20 marks
/21 marks
/17 marks
Application
/24 marks
Part A: Multiple Choice
[K/U]
/20 marks
Read each question carefully and choose the best answer. Write the letter of the answer and
circle the choice.
1. Which of the following statements about genes is false?
a) genes are made up of DNA
b) genes are found on chromosomes
c) genes are transmitted during sexual reproduction, but not during asexual
reproduction.
d) every individual inherits thousands of genes from each of his or her parents
e) genes can program cells to make enzymes or other proteins
2. Sexual and asexual reproduction are alike in that _______.
a) they both give rise to genetically distinct offspring
b) they both involve two parents
c) they both require meiosis to complete the reproductive cycle
d) they can both occur in multicellular organisms
e) in both cases, every parent transmit all of its genes to its progeny
3. Which of the following statements is false?
a) Diploid cells can divide by mitosis
b) Diploid cells can divide by meiosis
c) Haploid cells can divide by mitosis
d) Haploid cells can divide by meiosis
e) All of these statements are true.
4. In sexually reproducing species, the chromosome number remains stable over time
because ______ and _______ always alternate.
a) meiosis, fertilization
b) meiosis, mitosis
c) mitosis, fertilization
d) meiosis, interphase
e) meiosis I, meiosis II
5. Humans possess:
a) 22 pairs of sex chromosomes and 1 pair of autosomes
b) 23 pairs of autosomes
c) equal numbers of autosomes and sex chromosomes
d) 22 pairs of autosomes and 1pair of sex chromosomes
e) none of the above
Page 1 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
6. What is the result when a diploid cell undergoes meiosis?
a) two diploid cells
b) two haploid cells
c) four diploid cells
d) four haploid cells
e) two haploid cells and two diploid cells
7. Synapsis occurs during ______.
a) anaphase I
b) prophase I
c) cytokinesis
d) prophase II
e) metaphase I
8. During anaphase I ______.
a) homologous chromosomes separate and migrate toward opposite poles
b) sister chromatids separate and migrate toward opposite poles
c) nuclei reform
d) chromosomes line up in one plane
e) the cell is haploid
9. Which one of the following occurs in meiosis, but not mitosis?
a) The cells formed have the same combination of genes as found in the initial cell
b) Homologous chromosomes separate
c) The nuclear envelope disappears
d) Sister chromatids undergo disjunction
e) A spindle fibre forms
10. A tetrad is made up of:
a) two chromatids from one chromosome
b) one chromatid from two homologous chromosomes
c) four chromatids from two homologous chromosomes
d) one chromatid from one chromosome
e) none of the above
11. The major contribution of sex to evolution is ______.
a) It is the only mechanism for species to reproduce
b) It provides a method to increase genetic variation
c) It provides a way in which somatic mutations can be inherited
d) a) and b) are correct
e) a) and c) are correct
12. The law of independent assortment _______.
a) states that the alleles at different loci segregate independently form one another
during a dihybrid cross
b) can account for a 9: 3:3: 1 ratio seen in the F2 generation
Page 2 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
c) applies only to genes that are present on different chromosomes (or behave as if
they were)
d) a) and b) are correct
e) all of the above are correct
13. Drosophila is a useful organism for genetic studies for all of the following reasons
except:
a) They have a long generation time
b) A single mating can produce many offspring
c) They have a small number of chromosomes.
d) Drosophila chromosomes can be easily distinguishable under a light microscope
e) All of the above.
14. Wild type is referred to as:
a) the most common phenotype in the natural population
b) the most extreme mutant phenotype observed in an experiment
c) any mutant genotype
d) a kind of chromosomal deletion
e) extranuclear genes
15. What is the probability that a male will inherit an X-linked recessive allele from his
father?
a) 0%
b) 25%
c) 50%
d) 75%
e) 100%
16. Karyotypes are useful for:
a) determining whether or not the chromosomes are normal in number
b) determining whether or not the chromosomes are normal in structure
c) determining the sex of an individual
d) all of the above
e) none of the above
17. Which type of chromosomal alteration is responsible for the disorder Cri Du Chat?
a) inversion
b) duplication
c) genetic imprinting
d) deletion
e) translocation
18. Which one of the following is the only known viable human monosomy?
a) XYY
b) XO
c) YO
Page 3 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
d) XY
e) XXY
19. A woman is red-green color-blind. What can we conclude, if anything, about her father?
a) We have too little information to tell
b) There is a 50% probability that he has normal vision
c) He is red-green color-blind.
d) He has two Y chromosomes.
e) None of the above.
20. Cystic fibrosis, which is usually lethal before the age of reproduction, is a homozygous
recessive trait. Why do cases continue to arise, even though people with the disease
rarely live to reproduce?
a) Because new mutations continually introduce this harmful condition into the
population
b) Because the harmful allele “hides” within heterozygous individuals, one
fourth of the offspring of two heterozygotes would be afflicted
c) Because mosquitoes can transfer the disease form person to person
d) Because people continue to make inappropriate lifestyle choices
e) none of the above
Part B: Short Answer
1. Fill in the following chart.
[T/I]
/21 marks [C]
Mitosis
Number of times the cell
divides
Number of daughter cells
/17 marks
[A]
[T/I]
/5 marks
/7marks
Meiosis
1
2
2
4
Number of chromosomes
compared to the parent cell
Hint: use proper terms
Type of parent cell
Same as parents
diploid
Half as many as the parents
haploid
Any somatic cell
Reproductive cell
Type of daughter cell
Any somatic cell
Gamete (egg or sperm)
46
23
no
yes
Number of chromosomes in
daughter cell
Do homologous chromosomes
pair? Yes or No?
Page 4 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
2. Draw a diagram to illustrate the type of non disjunction that would cause a normal female and
a normal male to produce an XYY offspring and an XO offspring and indicate the name of the
resulting two genetic disorders.
[T/I]
/2marks [C]
/4 marks
Normal female
XX
X
X
XXY
Klinefelter syndrome
Normal Male
XY
XY
(4 marks for diagram)
O
XO
Turner’s syndrome
(2 marks for naming)
3. A man and a woman both have normal vision. They have three offspring, all of whom marry
people with normal vision. The three offspring and their children are as follows:
a) A son with red-green colour blindness who has a daughter with normal vision
b) A daughter who has three sons with normal vision
c) A daughter who has one red-green colour blind son and one son with normal vision
Draw the pedigree for this family, indicating the affected people and the carriers.
[T/I]
/5 marks (Correct labelling)
Carrier female
[C]
/5 marks (quality of diagram)
Colour-blind male
Page 5 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
4. Two couples had baby boys in the same hospital at the same time. There was a mix-up in the
hospital nursery. Using the information given in the table below, explain which baby belongs to
which family. Be sure to include Punnett squares in your answer.
Blood Type
[T/I]
Parent 1
B
Parent 1
AB
/5 marks (Correct assignment)
Parent 2
B
Parent 2
A
[C]
Baby 1
A
Baby 2
O
/5 marks (Quality of explanation)
Determine the genotypes of the blood types of the parents and babies.
Parent 1
Parent 1
Parent 2
Parent 2
Blood Type
B
AB
B
A
B
A B
B
Genotype
I i
I I
I i
IAi
Baby 1
A
IAi
Baby 2
O
ii
Use Punnett Squares to determine the possible genotypes of the babies
Couple 1
Couple 2
B
I
i
IA
IAIB
IA
IAi
IB
IBIB
IBi
i
IB
I I
IBi
i
IAi
ii
A B
Therefore, Baby 1 with Type A blood belongs to Couple 1 and Baby 2 with Type O blood
belongs to Couple 2.
5. A breeder wants to find out whether or not a certain golden retriever is a carrier for an
undesirable recessive trait. Explain what the breeder can do to find out. Show all work using
Punnett squares if necessary. [A] /3 marks
[C]
/3 marks (Quality of explanation)
Let G be the dominant trait and let g be the recessive trait.
To find out if the golden retriever has the recessive allele, breed it with a golden retriever with
the homologous recessive trait.
Possibility 1
g
g
Possibility 2
G
Gg
Gg
g
gg
gg
g
g
G
Gg
Gg
G
Gg
Gg
If the golden retriever is heterozygous i.e. is a carrier of the recessive trait as shown in possibility
1, then 50% of the pups will show the dominant trait and 50% will show the recessive trait.
If the golden retriever is homologous dominant i.e. not a carrier of the recessive trait as shown in
possibility 1, then all the pups will show the dominant trait.
6. Explain why marriages between very close relatives are illegal in Canada using genetics as the
basis of your explanation. [A] /2 marks
Page 6 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
The mating of two genetically related parents is known as inbreeding. Inbreeding results in
increased homozygosity which can increase the chances of offspring being affected by recessive
or deleterious traits, resulting in an increased risk of genetic disorders.
7. Briefly describe how geneticists would explain the following observations: [T/I]
a) a continuous distribution of phenotypes in traits such as eye colour
This observation can be explained by dominant and recessive traits.
/2 marks
b) the expression of an intermediate phenotype
This observation can be explained by incomplete or co-dominant traits.
Part C: Genetics Problems
[A]
/19 marks
Complete the following genetics problems. Show all your work. Be sure to include Punnett
squares in your answers if necessary.
1. A man with type O blood is married to a woman with type B blood. Which blood types can
their children have?
[A] /3 marks
Parental genotypes: ii and IBi or IBIB
Possibility 1
Possibility 2
B
i
i
I
IBi
IBi
A
I i
ii
ii
i
i
IB
IBi
IBi
IB
IBi
IBi
IBi = Type B blood and ii = Type O blood
Therefore, their children can only have Type O and Type B blood.
2. In horses, black colour (B) is due to a dominant allele and chestnut colour (b) is due to its
recessive allele. A pacing gate (T) is dominant over a trotting gait (t). A heterozygous black
pacer is crossed with a chestnut trotter. What are the possible genotypic and phenotypic ratios of
the F1 generation?
[A]
/5 marks
Let B represent the allele for black colour.
Let b represent the allele for chestnut colour.
Let T represent the allele for pacing gate.
Let t represent the allele for trotting gait.
Parental Genotypes: BbTt and bbtt
bt
bt
bt
BT
BbTt
BbTt
BbTt
Bt
Bbtt
Bbtt
Bbtt
bT
bbTt
bbTt
bbTt
bt
bbtt
bbtt
bbtt
Page 7 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
bt
Genetic Processes Unit Test
BbTt
Bbtt
Name: ___Answer Key___
Date:__________________
bbTt
bbtt
¼ BbTt Black Pacer, ¼ Bbtt Black Trotter, ¼ Chestnut Pacer, ¼ Chestnut Trotter
3. In cattle when a (RR) red bull is crossed with a (rr) white cow, the heterozygous offspring (Rr)
are neither red nor white but roan (red and white hair). Determine the phenotypic and genotypic
percentages for the offspring from a cross between a roan bull and a red cow. Show all work.
[A]
/3 marks
Let R represent the allele for red fur.
Let r represent the allele for white fur.
Parental Genotypes: Rr (roan bull) and RR (red cow)
R
R
R
RR
RR
r
Rr
Rr
Genotypes: 50% RR and 50% Rr
Phenotypes: 50% red fur and 50% roan
4. Colour blindness is inherited as an X-linked recessive. Tasting is an autosomal trait in which
tasting (T) is dominant to non-tasting (t). A heterozygous taster male that is colour-blind is
married to a non-taster female that is a carrier for colour-blindness. Use a complete Punnet
square to determine the answer to the following questions.
[A] 8 marks: 5 for the complete Punnet square and 3 for the answers to the questions
below.
a) If they have a daughter, what is the probability that she will be a taster and a colour-blind
carrier?
b) What is the probability of the couple having a non-taster colour-blind son?
c) What is the probability that the couple will have a taster child that is not colour-blind?
Parental Genotypes: Male: XCY and Tt
Colour Blindness
Taster
C
XC
X
Female: XCX and tt
X
XCXC
XCX
Y
XCY
XY
Colour Blindness
25% XCXC colour blind daughter
25% XCX carrier daughter
25% XCY colour blind son
25% XY normal son
t
t
T
Tt
Tt
t
tt
tt
Taster
50% Tt Taster
50% tt Non Taster
Page 8 of 9
SBI3U Grade 11 Biology
Unit: Genetic Processes
Genetic Processes Unit Test
Name: ___Answer Key___
Date:__________________
a) There is a 12.5% (0.25x 0.50= 0.125) chance that the couple will have a daughter who is a
taster and a colour-blind carrier.
b) There is a 12.5% (0.25x 0.50= 0.125) chance that the couple will have a non-taster colourblind son.
c) There is a 25% (0.50x 0.50 =0.25) chance that the couple will have a taster child that is not
colour-blind
Page 9 of 9