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Rhodes- Little
Name __________________________
Genetics Application Test
Date _________ Period ___
Mendel’s Experiments: Read the introduction for each section then answer the section questions that follow.
Before Mendel started cross-pollinating pea plants, he noticed that they always produced the same color flower
when they self-pollinated. A self-pollinating purple plant always produced plants with purple flowers and white
plants produced white flowering plants.
1. ________ What was the genotype of these true-breeding purple flowers?
2. ________ What was the genotype of these true-breeding white flowers?
Purple = P
White = p
In Mendel’s 1st experiment, he cross-pollinated the purple and white pea plants from above. This cross produced
purple pea plants. They never produced white plants even though there was a white parent plant.
3. Complete a Punnett square to show his cross-pollination of the purple and white plants.
Purple = P
White = p
4. ________ What was the genotype of these purple offspring that were produced from this cross?
5. _________________________________________ Why didn’t Mendel see any white flowered offspring
even though white alleles were being passed on to them?
In Mendel’s 2nd experiment, he allowed the purple offspring from the 1st experiment to self-pollinate. Normally a
self-pollinated purple plant would produce only purple plants. This time, however, something very unusual
happened. The self-pollinated purple plants produced both purple and white plants. In this experiment, Mendel
discovered the ratio between dominant and recessive traits was always 3 to 1.
6. Complete a Punnett square to show these self-pollinating purple plants.
Purple = P
White = p
7. _______, _______, _______ What were the genotypes of the 3 dominant purple offspring in this 3:1 ratio?
8. ________ What was the genotype of the 1 recessive white offspring in this 3:1 ratio?
Even though both parents were purple, they were able to produce a plant with a unique trait (white).
9. ________ What genotype did both purple parents have to be in order to produce this unique trait?
10. ________ What genotype did the white offspring have to be?
11. ______________________________________________________ Why wasn’t either parent plant white
even though both carried a white allele?
Mendel drew the following two conclusions from the results of his experiments:
 Each plant must have two sets of instructions for each characteristic.
 Each parent plant must donate one set of instructions for each characteristic to its offspring.
12. ______________
What do we now call the two sets of instructions that Mendel identified?
13. ______________
What do we now call the one set of donated instructions that Mendel talked about?
14. ______________
What was the phenotype of the recessive pea plant in these two experiments?
15. ______________________________________________ Explain why you chose this as the recessive trait?
______________________________________________ (Use Mendel’s experimental results to explain.)
CONTINUED ON BACK!
Reebop Reflections: Answer each question completely to show your level of understanding.
16. ______________
What did each strip of paper (pink or blue) represent in the Reebop lab?
17. ______________
What did a pair of paper strips (pink and blue) placed together represent in the Reebop lab?
18. ___________________
Some of the Reebop children had unique traits that neither parent had. For this to
What genotype for that trait would both parents have to be for this to happen?
(Choices: pure dominant, pure recessive or heterozygous).
19. ___________________
What genotype would the unique, baby Reebops have to be for that trait?
20. _________________________________________ What do you have to do to figure out if a trait is
dominant or recessive for all of the baby Reebops?
Widow’s Peak Predictions:
Widow’s Peak = W
Straight Hairline = w
21. ____________________
What are all of the possible genotypes that would produce a straight hairline?
22. ____________________
What are all of the possible genotypes that would produce a widow’s peak?
23. Complete a Punnett square to determine the possible offspring if you cross a
a heterozygous parent for widow’s peak with another heterozygous parent.
24. The probability the offspring will be: pure dominant =_____% pure recessive =_____% heterozygous =_____%
25. The probability the children will have: a straight hairline =_____% a widow’s peak =_____%
Eye Color Calculations:
Dark Eyes = D
Light Eyes = d
26. __________________What is the phenotype for Dd?
27. __________________ What is the phenotype for dd?
28. _________________________________ When does the phenotype of a trait always tell you the genotype of a trait?
(Choices: when the trait is dominant or when it is recessive or both)
Use a Punnett square to determine the parents’ genotypes for each family below.
29. Parents = 1 light and 1 dark
Children: 4 dark
Parent’s genotype: _______ and _______
Blood Types:
Type A
Type B
Type AB
Dark Eyes = D
Light Eyes = d
30. Parents = 1 light and 1 dark
Children: 2 dark and 2 light
Parent’s genotype: _______ and _______
Type O
31. ________ Which of the phenotypes above is a co-dominant blood type?
32. _______________ Which blood types above have more than one genotype combination to produce that blood type?
33. ______________________________________________________ Explain how it’s possible for a child to have
type O blood if neither parent’s phenotype is O?
Use a Punnett square to determine the possible offspring
from a homozygous B and a heterozygous A parent.
From the offspring in this Punnett square:
34. All possible genotypes = ____________________
Type A = A Type AB = AB
Type B = B Type O = o
35. All possible phenotypes (blood types) = ________________
Assume a family has one child with blood type B, another with type O, and a third is type A. (Show your work.)
36. ______________________ and ______________________ What are the genotypes of both parents?
Type A = A Type AB = AB
Type B = B Type O = o
KEY
+1 per correct answer
Genetics Application Test
1. PP
2. pp
3.
24. 25% 25% 50% (IN ORDER) +3
p
P
Pp
P
Pp
p
Pp
Pp
25. 25% 75% (IN ORDER) +2
+1 Punnett square
26. dark eyes
27. light eyes
4. Pp
28. when the trait is recessive
5. All of the offspring were heterozygous (Pp)
so the dominant purple (P) covered-up the
recessive white (p)
29. DD and dd (no order) +2
D
D
d
Dd
Dd
+1 Punnett square
d
Dd
Dd
6.
P
P
PP
p
Pp
p
Pp
pp
+1 Punnett square
7. PP, Pp, Pp (no order) +3
8. pp
9. Pp
30. Dd and dd (no order) +2
D
d
d
Dd
dd
+1 Punnett square
d
Dd
dd
31. AB
10. pp
32. type A and type B +2
11. Both parents were heterozygous so the
dominant purple covered the recessive white.
33. When each parent has one O allele (Ao or Bo)
34. Bo and AB (no order) +2
12. a gene pair
35. type B and type AB +2
13. a gene
14. white
15. white appeared less often OR white got
covered-up by the purple plants
+1
A
B
AB
22. WW and Ww
23.
W
W WW
w
Ww
+2
w
Ww
ww
Bo
Bo
o
Bo
o
Ao
oo Punnett square
19. pure recessive
21. ww
o
36. Ao and Bo (no order) +2
17. a gene pair
20. look for which trait occurred more/less often
B
AB
+1 Punnett square
16. a gene
18. heterozygous
A
B
AB
TOTAL POSSIBLE = +52
A = 47-52
B = 42-46
Test Retakes
C = 36-41
D = 31-35
F = 0-20