Download Genetics Practice Set #1

Genetics Practice Set #1
1) The D gene controls pea plant height. The DD and dd genotypes
confer tall and dwarf phenotypes, respectively. What is the
relationship between D and d?
A) They are two different plant chromosomes.
B) They are alleles of the same gene.
C) They are two different genes on the same chromosome.
D) They are two possible homozygous genotypes.
E) They are two possible heterozygous genotypes.
2) In Mendel's basic experiment, he began with true-breeding parental (P) plants. What did he
see when he cross-fertilized P plants that had different traits?
A) All F1 plants had the trait of one or the other P plant.
B) The F1 plants showed a combination of the two P traits, in a 3:1 ratio.
C) The F1 plants showed a combination of the two P traits in a 1:1 ratio.
D) The F1 plants had new traits that were a blend of P traits.
E) The F1 plants had an entirely new trait, not seen in either P plant.
3) Crossing red flowering snapdragons with white flowering snapdragons yields seed that grow
into snapdragons with pink flowers.
A) These mating results support the blending hypothesis of inheritance.
B) These mating results support the hypothesis that there are unblended discrete units of
inheritance.
4) Crossing two pink snapdragons yields some seed that produces red flowering plants, some
seed that produces white flowering plants and some seed that produces pink flowering plants.
A) These mating results support the blending hypothesis of inheritance.
B) These mating results support the hypothesis that there are unblended discrete units of
inheritance.
Use this information for the two question #5-6.
A and a are dominant and recessive alleles, respectively, of the same gene.
5) Which genotype(s) would result in an individual with the dominant phenotype?
A) AA and aa B) AA and Aa C) Aa and aa D) only AA E) only Aa
6) Which genotype(s) would result in an individual with the recessive phenotype?
A) aa only B) Aa only C) Aa or aa D) AA only E) AA or aa
Use this information for the four question #8-10.
Cystic fibrosis (CF) is caused by a recessive allele. A child has CF, even though neither of his
parents has CF. Use this information for the questions below.
7) What can you conclude about the parents?
A) They are both homozygous dominant for the CF gene.
B) They are both homozygous recessive for the CF gene.
C) One is homozygous dominant for the CF gene, the other is heterozygous.
D) One is homozygous recessive for the CF gene, the other is heterozygous.
E) They are both heterozygous for the CF gene.
8) This couple has another child who does not have CF. What is the probability he or she is
heterozygous?
A) 1/4 B) 2/4 C) 3/4 D) 1/3 E) 2/3
9) If this couple has another child, what is the probability he or she will NOT have CF?
A) 1/4 B) 2/4 C) 3/4 D) 1/3 E) 2/3
10) If this couple has another child, what is the probability it will be a boy, with CF?
A) 1/32 B) 1/20 C) 1/16 D) 1/10 E) 1/8
11) Widows peak hairline in humans is dominant to non-widows peak hairline. If a person has a
widows peak hairline, what is his or her genotype?
A) It must be homozygous dominant.
B) It must be homozygous recessive.
C) It is either homozygous dominant or homozygous recessive.
D) It must be heterozygous.
E) It is are either heterozygous or homozygous dominant.
Answers:
1. B
2. A
3. A
4. B
5. B
6. A
7. E
8. E
9. C
10. E
11. E
Genetics Practice Set #2
Bikini Bottom Genetics 2:
Use your knowledge of genetics to complete this worksheet.
1. Use the information for SpongeBob’s traits to write the
phenotype (physical appearance) for each item.
Characteristic
Body Shape
Body Color
Eye Shape
Nose Style
Dominant Gene
Squarepants (S)
Yellow (Y)
Round (R)
Long (L)
Recessive Gene
Roundpants (s)
Blue (y)
Oval (r)
Stubby (l)
(a) LL-______________
(e) Rr-_______________
(b) yy-_______________
(f) ll- _______________
(c) Ss-_______________
(g) ss- _______________
(d) RR - _____________
(h) Yy -______________
2. Use the information in the chart in #1 to write the genotype (or genotypes) for
each trait below.
(a) Yellow body - ___________ (e) Stubby nose - ___________
(b) Roundpants - ___________ (f) Round eyes - ____________
(c) Oval eyes - ______________ (g) Squarepants - ___________
(d) Long nose - _____________ (h) Blue body - ____________
3. Determine the genotypes for each using the information in the chart in #1.
(a) Heterozygous round eyes -_____ (c) Homozygous long nose - ______
(b) Purebred squarepants - ______ (d) Hybrid yellow body - ______
4. One of SpongeBob’s cousins, SpongeBillyBob, recently met a cute
squarepants gal, SpongeGerdy, at a local dance and fell in love. Use your
knowledge of genetics to answer the questions below.
(a) If SpongeGerdy’s father is a heterozygous squarepants and her mother is a
roundpants, what is her genotype? Complete the Punnett square to show the
possible genotypes that would result to help you determine Gerdy’s genotype.
What is Gerdy’s genotype? _________
(b) SpongeBillyBob is heterozygous for his squarepants shape. What is his
genotype? ________
(c) Complete the Punnett square to show the possibilities that would result if Billy
Bob & Gerdy had children.
(d) List the possible genotypes and phenotypes for the kids.
(e) What is the probability of kids with squarepants? _____ %
(f) What is the probability of kids with roundpants? _____ %
5. SpongeBob’s aunt and uncle, SpongeWilma and SpongeWilbur, have the
biggest round eyes in the family. Wilma is believed to be heterozygous for her
round eye shape, while Wilbur’s family brags that they are a pure line.
Complete the Punnett square to show the possibilities that would result if
SpongeWilma and SpongeWilbur had children.
(a) Give the genotype for each person. Wilma - _______ Wilbur - ________
(b) Complete the Punnett square to show the possibilities that would result if they
had children.
(c) List the possible genotypes and phenotypes for the kids.
(d) What is the probability that the kids would have round eyes? ____ %
(e) What is the probability that the kids would be oval eyes? ____ %
6. SpongeBob’s mother is so proud of her son and his new wife, SpongeSusie,
as they are expecting a little sponge. She knows that they have a 50% chance
of having a little roundpants, but is also hoping the new arrival will be blue (a
recessive trait) like SpongeSusie and many members of her family. If
SpongeBob is heterozygous for his yellow body color, what are the chances
that the baby sponge will be blue? Create a Punnett square to help you
answer this question.
Pgen:
Gametes:
Square
7. SpongeBob’s aunt is famous around town for her itty, bitty stubby nose! She
recently met a cute squarepants fellow who also has a stubby nose, which is a
recessive trait. Would it be possible for them to have a child with a regular long
nose? Why or why not? Create a Punnett square to help you answer this
question.
Pgen:
Gametes:
Square:
8. If SpongeBob’s aunt described in #7 wanted children with long noses, what
type of fellow would she need to marry in order to give her the best chances?
Create a Punnett square to help you answer this question.
Pgen:
Gametes:
Square
Genetics Practice Set #3
Set up the Punnet squares for each of the crosses listed below.
Round seeds are dominant to wrinkled seeds.
1. Rr x rr
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be round? _______________
2. RR x rr
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be round? _______________
3. RR x Rr
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be round? _______________
4. Rr x Rr
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be round? _______________
5. A TT (tall) plant is crossed with a tt (short plant).
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be tall? _______________
6. A Tt plant is crossed with a Tt plant.
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be short? _______________
7. A heterozygous round seed plant (Rr) is crossed w/ a homozygous round seed plant
(RR).
a. What are the different kinds of gametes these parents can produce?
___________
b. Make a punnett square
c. What percentage of the offspring will be homozygous (RR)? __________
8. A homozygous round seeded plant is crossed with a homozygous wrinkled seeded
plant.
a. What are the genotypes of the parents? __________ x __________
b. What are the different kinds of gametes these parents can produce?
c. Make a punnett square
d. What percentage of the offspring will also be homozygous? ___________
9. In guinea pigs, the allele for short hair is dominant.
a. What genotype would a heterozygous short haired guinea pig have? _______
b. What genotype would a purebred short haired guinea pig have? _______
c. What genotype would a long haired guinea pig have? ________
10. Show the cross for a pure breeding short haired guinea pig and a long haired guinea
pig.
a. What percentage of the offspring will have short hair? __________
11. Show the cross for two heterozygous guinea pigs.
a. What percentage of the offspring will have short hair? ________
b. What percentage of the offspring will have long hair? _______
12. Two short haired guinea pigs are mated several times. Out of 100 offspring, 25 of
them have long hair. What are the probable genotypes of the parents? Show work!