Download Part A: Multiple Choice. Choose the BEST answer. (1 point each x

Name:_____________________
October 4, 2013
Gr.12 Biology: Genetics
Part A: Multiple Choice. Choose the BEST answer. (1 point each x 17= 17 marks)
1. _____ An allele is ___.
A.
B.
C.
D.
E.
one of the bases in DNA
an alternate form of a gene
another term for epistasis
present only in males and is responsible for sex determination
found in mitochondria but not in nuclei
2. _____ What would be the smallest dimensions possible for a Punnett square for the cross Ww x ww?
A.
B.
C.
D.
4x4
2x2
2x1
1x1
3. _____ In dihybrid crosses, the ratio 9:3:3:1 indicates ___.
A.
B.
C.
D.
Codominance
Independent assortment
Intermediate dominance
Three alleles for each trait
4. _____In a cross of a round hybrid pea with a true breeding round parent (Ww x WW), what genotypic
proportions would be observed in the offspring?
A.
B.
C.
D.
Half heterozygous, half homozygous dominant
Half round, half wrinkled
All heterozygous
All round
5. _____ The fundamental Mendelian process which involves the separation of contrasting genetic
elements at the same locus would be called ___.
A.
B.
C.
D.
E.
segregation
independent assortment
continuous variation
discontinuous variation
dominance or recessiveness
6. _____There are three different genotypes resulting from a monohybrid cross. How many different
genotypes would there be resulting from a dihybrid cross?
A.
B.
C.
D.
4
8
9
16
7. _____ Starting with a cross between AA and aa, the proportion of heterozygotes in the F2 progeny
will be ___.
A.
B.
C.
D.
E.
1/8
1/4
1/3
1/2
All heterozygotes
8. _____ Albinism, lack of pigmentation in humans, results from an autosomal recessive gene. Two
parents with normal pigmentation have an albino child. What is the probability that their next child will
be albino?
A.
B.
C.
D.
1/2
1/4
1/8
1/16
9. _____ A species of mice can have gray or black fur and long or short tails. A cross between blackfurred, long-tailed mice and gray-furred, short-tailed mice produce all black-furred, long-tailed offspring.
Using the gene symbols G for black, g for gray, S for long and s for short, what would be the genotype of
a gray-furred, short-tailed mouse?
A.
B.
C.
D.
E.
GGSS
ggSS
ggss
GgSs
Ggss
10. _____ Referring to question 9, how many different gametes will the black-furred, long-tailed P1 mice
produce?
A.
B.
C.
D.
1
2
4
16
11. _____ What would be the minimum dimensions of a Punnett Square for a dihybrid cross?
A.
B.
C.
D.
1x4
2x4
4x4
2 x 2.
12. _____ To determine if an organism with a dominant phenotype is heterozygous or homozygous
dominant, one can perform a ___________.
A.
B.
C.
D.
reciprocal cross
dihybrid cross
test cross
Mendelian twist
13. _____ Which of the following conditions is/are autosomal?
A.
B.
C.
D.
E.
F.
G.
H.
Duchenne Muscular Dystrophy
Tay Sachs Disease
Hemophilia
Cystic Fibrosis
Huntington’s Disease
B and E
B, D, and E
A, B, and E
14. ____ In a linkage group:
A. All alleles are on one chromosome
B. Tend to be inherited together
C. If two traits are in one linkage group, then the cross will have similar results as if you had a onetrait cross
D. Only two gametes are possible
E. All of the above are true
F. None of the above are true
15. ____ A Barr body:
A.
B.
C.
D.
Explains what causes Down Syndrome
Explains why a female with Turner Syndrome has a high probability of surviving
is the extra active X chromosome in normal females
Explains why poly-X females have a high probability of spontaneous abortion.
15. _____ Skin colour, eye colour, and hair colour are examples of what type of inheritance?
A.
B.
C.
D.
incomplete dominance
codominance
polygenic inheritance
multiple alleles
E. all of the above
16. ____Down Syndrome is:
A.
B.
C.
D.
E.
F.
G.
H.
I.
trisomy 21
caused by nondisjunction
caused by crossing-over
autosomal
sex-linked
A,B, and E are true
A, B and D are true
A, C, and D are true
A, C, and E are true
17. _____ Curly, straight and wavy hair are an example of:
A.
B.
C.
D.
E.
codominance
incomplete dominance
polygenic inheritance
multiple alleles
none of the above
Part B: Short Answer (18 marks)
1. (3) A certain type of congenital deafness in humans is caused by a rare autosomal dominant gene. In
a mating involving a deaf man and a deaf woman, could all the children have normal hearing? Explain
using a Punnett square to prove your answer is possible. What is the probability of having a normal
hearing child from these parents?
2. (7) In Oompah genetics, being gray-faced is dominant over being orange faced. Purple, red, and blue
hair colour exhibit incomplete dominance. If Olivia Oompah, who is heterozygous for a gray face and
has purple hair, has children with Oliver Oompah, who has an orange face and red hair, what proportion
of their children will have a:
A. Gray face
_____________
B. orange face _____________
C. Red hair _____________
D. Purple hair _____________
E. blue hair_____________
F. Gray face and red hair _______
G. Orange face and blue hair _______
3. (2) Explain how crossing-over increases genetic variation. Draw a diagram as part of your
explanation.
4. In the 1950’s, a young woman sued film star/director Charlie Chaplin for parental support of
her illegitimate child. Charlie Chaplin’s blood type was already on record as type AB. The
mother of the child had type A and her son had type O blood.
a. (4) Complete a Punnett square(s) for the possible cross(es) of Charlie and the
mother.
b. (2) The judge ruled in favor of the mother and ordered Charlie Chaplin to pay
child support costs of the child. Was the judge correct in his decision based on
blood typing evidence? Explain why or why not using the information in your
Punnett square(s).
Part C: Pedigree Analysis (10 points)
Examine the following pedigree for a genetic disorder:
(Assume that I-2 is NOT a carrier.)
1.(6) Determine whether the condition is autosomal dominant, autosomal recessive or X-linked
recessive. Explain the reason for your choice, as well as your reason for eliminating the other two
options.
2. (4) Write the genotypes of the following individuals below. If there is more than one possible
genotype, then write down both possibilities.
I-1:______
I-2:______
II-2:______
II-3:______
II-5:______
III-2:______
III-5:______
III-6:______
3. (4) What are the 4 structural changes (mutations) that can occur during gamete formation? List
them, and use diagrams to explain what they are.
Part D: Long Answer
Answer
2 of the following 3 questions (10 marks)
(I will only mark the first three questions if you answer all four.)
Be specific in your answers. Prove to me that you learned something this unit!
1. (5) What is karyotyping? Explain what it is, and then explain the two
methods of karyotyping we learned about in class, along with their risks and
benefits.
2. (5) Would you get genetic testing done on yourself for an inherited
condition? Include details that support your opinion based on the
information studied in class.
3. (5) Explain how sex-linked inheritance was at least a contributing factor in
the demise of many of the kingdoms of Europe.
Total: ____/55