Download Ch 10 test 04-05

Lab Biology
Name _____________________________
Mendelian Genetics Exam: Chapter 10
Mutiple Choice. Choose the best answer for each question. 2 pts each.
_____1. A variation of a gene is called a(n):
a. allele
b. chromosome
c. mutation
d. trait
_____ 2. A student crosses wrinkled-seeded (rr) pea plants with round-seeded (RR) pea plants. Only
round seeds were produced in the resulting plants. This illustrates the principle of
a. dominance & recessiveness
b. pollination
c. segregation
d. independent assortment
_____3. Uppercase letters represent ______________ alleles.
a. independent
b. genetic
c. recessive
d. dominant
_____ 4. Mendel obtained his P1 generation by allowing the pea plants to:
a. segregate
b. independently assort
c. self-pollinate
d. cross-pollinate
_____ 5. Which genetic principle states that genes are distributed to gametes in a random fashion?
a. mutation
b. dominance
c. independent assortment
d. segregation
_____ 6. The appearance of a recessive trait in offspring of animals most probably indicates:
a. one parent was homozygous dominant and the other parent was homozygous recessive for
that trait
b. both parents carried at least one recessive gene for that trait
c. neither parent carried recessive genes for that trait
d. one parent was homozygous dominant and the other parent was heterozygous for that trait
Create a punnett square to solve the following problems. Show the parental genotypes, and
phenotypic/genotypic results of the offspring for every problem. Unless otherwise indicated, you
will receive 2 points for showing the correct parental genotypes, 2 points for showing the correct offspring
genotypes based on your parents, and 2 points for each correct ratio and answer to additional questions
based on your offspring genotypes.
7. In pigs, a curly tail is dominant over a straight tail. Show the cross between two straight-tailed pigs.
(8 pts)
a) Offspring genotypic ratio: ________________________
_______________________________________________
b) Offspring phenotypic ratio:________________________
_____________________________________________
8. In pea plants, tallness is due to a dominant allele and shortness to the recessive allele. Show the
cross between a homozygous dominant plant and a heterozygous plant. (8 pts)
a) Offspring genotypic ratio: ___________________________
__________________________________________________
b) Offspring phenotypic ratio:___________________________
_________________________________________________
9. In humans, dimples are a dominant trait. Having no dimples is recessive. Show the cross between
two people who are both heterozygous for dimples. (10 pts)
a) Offspring genotypic ratio: _________________________
_______________________________________________
b) Offspring phenotypic ratio: ________________________
_______________________________________________
c) What are the chances that they will have a child without dimples?____________________
10. In the Munster family, green skin is dominant to white skin. Herman Munster and his wife have four
children. Two of the children are heterozygous for green skin and the other two have white skin.
What are the phenotypes and genotypes of the parents? (8 pts = 4 points for offspring genotypes, 2
points for parental genotypes, 2 points for parental phenotypes)
a) Genotypes of Parents:________________________
b) Phenotypes of Parents: _______________________
11. In the human population, brown eyes are dominant to blue eyes. Show a cross between a man with
blue eyes and a woman who is pure for brown eyes. (10 pts)
a) Offspring genotypic ratio: ___________________________
_____________________________________________
b) Offspring phenotypic ratio: __________________________
________________________________________________
c) What are the chances that they will have a child who has blue eyes?________________
12. Japanese four o’ clocks are flowers that exhibit incomplete dominance. Neither red flowers (R) nor
white flowers (W) are dominant. Show a cross between a red flower and pink flower. (8 pts)
a) Offspring genotypic ratio: _________________________
_______________________________________________
b) Offspring phenotypic ratio: ________________________
_______________________________________________
13. In rabbits, black coat color is dominant to white coat color. A breeder of rabbits has just received
some black rabbits whose parents are unknown. He wants to make sure that the rabbits are pure
for black coat color. The breeder performs a testcross and gets the following results: 2 black
bunnies and 2 white bunnies. Show the testcross that would yield these results. (10 pts)
a) What is the known genotype of the rabbit used to
perform the testcross? ________________
b) What is the genotype of the black rabbit? __________
c) Is the rabbit pure for black coat color? ____________
14. In pea plants, green pods are dominant to yellow pods. Show a cross between a plant that is
pure for green pods and a pure yellow pod plant. (8 pts)
a) Offspring genotypic ratio: _________________________
________________________________________________
b) Offspring phenotypic ratio:_________________________
15. In humans, unattached earlobes are dominant over attached earlobes. Determine the
phenotypic and genotypic percentages of a cross between a heterozygous woman and a man
with attached earlobes. (8 pts)
a) Offspring genotypic ratio: _________________________
________________________________________________
b) Offspring phenotypic ratio:_________________________
________________________________________________
Use the dihybrid punnett square below to answer questions 16-20. Remember: Round seeds are
dominant to wrinkled, and yellow seeds are dominant to green. 2 pts each
RY
RY
X
Ry
Ry
rY
2
rY
6
ry
1
3
5
4
ry
_____ 16. The phenotype represented by the box labeled 1 is:
a. round, yellow
b. round, green
c. wrinkled, yellow
d. wrinkled, green
_____ 17. The genotype represented by the box labeled 2 is:
a. RRYY
b. RrYY
c. RrYy
d. rrYy
_____ 18. Which of the following boxes represents the same phenotype as the box
labeled X?
a. 3
b. 4
c. 5
_____19. The genotypes of the parents are:
a. RRYy x Rryy
b. RrYy x RRYY
_____20. The phenotypes of the parents are:
a. round, yellow x round, green
b. wrinkled, yellow x round, green
c. round, yellow x round, yellow
d. wrinkled, green x round, green
c. RrYy x RrYy
d. rrYy x Rryy
d. 6