Transcript File

T. Trimpe 2008 http://sciencespot.net/
1. Predict the offspring from a cross between a purebred tall pea plant
and a hybrid tall plant. Use T for tall and t for short.
(a) Give the genotypes.
Purebred Tall = ____
Hybrid Tall = ____
(b) Create a Punnett square to determine the genotypes for the offspring.
(c) What is the probability that a plant would be tall? _______ %
(d) What is the probability that a plant would be short? _______ %
2. Predict the offspring from a cross between two hybrid tall pea plants.
(a) Give the genotype for a hybrid tall plant. ______
(b) Create a Punnett square to determine the genotypes for the offspring.
(c) What is the probability that a plant would be tall? _____ %
(d) What is the probability that a plant would be short? _____ %
(e) If you were to plant 100 seeds from this cross, how many would you expect to
be tall?
1. Predict the offspring from a cross between a purebred tall pea plant and a
hybrid tall plant. Use T for tall and t for short.
(a) Give the genotypes.
TT
Purebred Tall = ____
Tt
Hybrid Tall = ____
(b) Create a Punnett square to determine the genotypes for the offspring.
T
t
T TT Tt
T TT
Tt
(c) What is the probability that a plant would be tall?
(d) What is the probability that a plant would be short?
100%
0%
2. Predict the offspring from a cross between two hybrid tall pea plants.
Tt
(a) Give the genotype for a hybrid tall plant. ______
(b) Create a Punnett square to determine the genotypes for the offspring.
T
t
T TT Tt
t
Tt
tt
(c) What is the probability that a plant would be tall?
75%
(d) What is the probability that a plant would be short?
25%
(e) If you were to plant 100 seeds from this cross, how many would you expect to
be tall?
25% of 100 = 25 plants
T. Trimpe 2008 http://sciencespot.net/
1. Predict the offspring from a cross between a purebred pea plant with purple
flowers and a pea plant with white flowers. Use P for purple and p for white.
(a) Give the genotypes.
Purebred Purple = ____
White = ____
(b) Create a Punnett square to determine the genotypes for the offspring.
(c) What is the probability that a plant would have purple flowers? _______ %
(d) What is the probability that a plant would have white flowers? _______ %
2. If you crossed two hybrid plants with purple flowers and planted 200 of the
seeds, how many would you expect to have with white flowers. Create a
Punnett square to support your answer.
1. Predict the offspring from a cross between a purebred pea plant with purple
flowers and a pea plant with white flowers. Use P for purple and p for white.
(a) Give the genotypes.
PP
Purebred Purple = ____
pp
White = ____
(b) Create a Punnett square to determine the genotypes for the offspring.
p
p
P
Pp
Pp
P
Pp
Pp
(c) What is the probability that a plant would have purple flowers? 100%
(d) What is the probability that a plant would have white flowers?
0%
2. If you crossed two hybrid plants with purple flowers and planted 200 of the
seeds, how many would you expect to have with white flowers. Create a
Punnett square to support your answer.
P
P
p
p
PP Pp
Pp
pp
You would expect to see white flowers
on 25% of the plants, which would be
50 plants.
T. Trimpe 2008 http://sciencespot.net/
Some people have dimples, while others do not. The presence of dimples is a
dominant trait (D), while not having dimples is recessive (d).
(1) Susie has dimples, but her husband, Tom, does not. Their first child has his
father's phenotype. What are the genotypes of the mother, father, and child?
Mother’s Genotype: _______
Father’s Genotype: _______
Son’s Genotype: _______
(2) What is the probability that a second child won’t have dimples? Create a
Punnett square to support your answer.
Some people have dimples, while others do not. The presence of dimples is a
dominant trait (D), while not having dimples is recessive (d).
(1) Susie has dimples, but her husband, Tom, does not. Their first child has his
father's phenotype. What are the genotypes of the mother, father, and child?
Dd
Mother’s Genotype: _______
dd
Father’s Genotype: _______
dd
Son’s Genotype: _______
(2) What is the probability that a second child
won’t have dimples? Create a Punnett square
to support your answer.
d
d
D Dd Dd
There would be a 50% probability that the
second child would not have dimples.
d
dd
dd
T. Trimpe 2008 http://sciencespot.net/
In Dalmatians, the trait for black spots (B) is dominant over the
recessive trait for no spots. Use this information to answer
these questions.
(1) Two Dalmatians with black spots have puppies. One of the dogs is
homozygous for black spots, while the other is heterozygous. Out of a litter of
4 puppies, how many would you expect to have without spots? Create a
Punnett square to support your answer.
(2) Two Dalmatians had a large litter of 10 puppies. Seven of them have black
spots, while 3 do not. What would the genotypes of the two parents need to be
for this result? Create a Punnett square to support your answer.
(1) Two Dalmatians with black spots have puppies. One of the dogs is
homozygous for black spots, while the other is heterozygous. Out of a litter of
4 puppies, how many would you expect to have without spots? Create a
Punnett square to support your answer.
B
B
B BB BB
b
Bb Bb
None of them would be all white, since all
the offspring would have black spots.
(2) Two Dalmatians had a large litter of 10 puppies. Seven of them have black
spots, while 3 do not. What would the genotypes of the two parents need to be
for this result? Create a Punnett square to support your answer.
B
B
B
b
B
b
B BB BB
b
Bb
bb
B BB Bb
Bb Bb
b
Bb
bb
b
b
Bb
bb
The parents would have both have to be Bb or heterozygous for black spots
in order to have 7 out of 10 or about 75% of puppies with black spots.
T. Trimpe 2008 http://sciencespot.net/
1. One of SpongeBob’s cousins with hybrid round eyes (Rr) had children with
someone who also had hybrid round eyes (Rr).
A. Create a Punnett square to show the possible offspring that would result
from this cross.
B. Give the genotypes and phenotypes of the offspring.
C. What percentage of the children should have round eyes?
2. Another of SpongeBob’s cousins with hybrid round eyes (Rr) had children
with someone who has oval eyes (rr).
A. Create a Punnett square to show the possible offspring that would result
from this cross.
B. Give the genotypes and phenotypes of the offspring.
C. What percentage of the children should have round eyes?
1. One of SpongeBob’s cousins with hybrid round eyes (Rr) had children with
someone who also had hybrid round eyes (Rr).
A. Create a Punnett square to show the possible offspring that would result from
this cross.
R
r
R RR Rr
r
Rr
rr
B. Give the genotypes and phenotypes of the offspring.
RR = Round eyes
Rr = Round eyes
rr = Oval eyes
C. What percentage of the children should have round eyes?
75%
2. One of SpongeBob’s cousins with hybrid round eyes (Rr) had children with
someone who has oval eyes (rr).
A. Create a Punnett square to show the possible offspring that would result from
this cross.
r
r
R Rr
Rr
rr
rr
r
B. Give the genotypes and phenotypes of the offspring.
C. What percentage of the children should have round eyes?
Rr = Round eyes
rr = Oval eyes
50%