Bio 156 lab 7 genetics
1. List whether the student was positive or negative for each characteristic and include whether the characteristic is dominant or recessive. (6 points)
a. Blood type- O
b. Widow's peak- Negative, resessive.
c. Free ear lobes- Positive, dominant.
d. Tongue rolling- Positive, dominant.
e. Hitchhiker's thumb- Negative, dominant.
f. Left thumb dominance- Negative, reseesive.
g. Little finger bend- Positive, dominant.
h. PTC taster- Negative, resessive.
i. Mid-digit hair- Negative, recessive.
j. Facial dimples- positive,dominant.
k. Freckles- Positive, dominant.
l. Cleft chin- negative, resseive.
2. Can the student tell from the blood type if the student is heterozygous or homozygous? Explain. (5 points) Yes, knowing your blood type would enable you to determine it you are heterozygous or homeqygous. Examples of this would be BB is homozygous, and BO is heterozygous. If the student has an A bloodtype, AO would be herterozygous while AA homozygous. The O blood type is always homozygous and AB blood type in always heterozygous.
3. Select a trait of interest.
a. What is the trait? (1 point)
b. What is the phenotype for the trait? Is this the dominant or recessive allele for the trait? (2 points)
c. What are the possible genotypes for the parents? (2 points)
d. Include the results of one Punnett square, showing a possible combination between alleles for the trait from the parents by filling in the genotypes according to the numbers in the square, below. 1
2
3
5
6
4
7
8
e. Based on the cross, what percent of children born to the parents would express the trait? (1 point)
4. Create a Punnett square to determine the possibility of a couple having a color-blind child if the mother has the recessive trait on one X and the father is color-blind. HINT: Use Xb to indicate an X with the color-blindness trait. How many female offspring will be color-blind? How many male offspring? (5 points) If the couple were to produce four children, there would be a 50% chance that one
a. Blood type- O
b. Widow's peak- Negative, resessive.
c. Free ear lobes- Positive, dominant.
d. Tongue rolling- Positive, dominant.
e. Hitchhiker's thumb- Negative, dominant.
f. Left thumb dominance- Negative, reseesive.
g. Little finger bend- Positive, dominant.
h. PTC taster- Negative, resessive.
i. Mid-digit hair- Negative, recessive.
j. Facial dimples- positive,dominant.
k. Freckles- Positive, dominant.
l. Cleft chin- negative, resseive.
2. Can the student tell from the blood type if the student is heterozygous or homozygous? Explain. (5 points) Yes, knowing your blood type would enable you to determine it you are heterozygous or homeqygous. Examples of this would be BB is homozygous, and BO is heterozygous. If the student has an A bloodtype, AO would be herterozygous while AA homozygous. The O blood type is always homozygous and AB blood type in always heterozygous.
3. Select a trait of interest.
a. What is the trait? (1 point)
b. What is the phenotype for the trait? Is this the dominant or recessive allele for the trait? (2 points)
c. What are the possible genotypes for the parents? (2 points)
d. Include the results of one Punnett square, showing a possible combination between alleles for the trait from the parents by filling in the genotypes according to the numbers in the square, below. 1
2
3
5
6
4
7
8
e. Based on the cross, what percent of children born to the parents would express the trait? (1 point)
4. Create a Punnett square to determine the possibility of a couple having a color-blind child if the mother has the recessive trait on one X and the father is color-blind. HINT: Use Xb to indicate an X with the color-blindness trait. How many female offspring will be color-blind? How many male offspring? (5 points) If the couple were to produce four children, there would be a 50% chance that one