Bio lab 156 lab 7
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
b. Widow's peak yes, +
c. Free ear lobes yes, +
d. Tongue rolling yes, +
e. Hitchhiker's thumb yes, +
f. Left thumb dominance yes, +
g. Little finger bend
h. PTC taster yes, +
i. Mid-digit hair no, -
j. Facial dimples yes, +
k. Freckles no, -
l. Cleft chin no, -
2. Can the student tell from the blood type if the student is heterozygous or homozygous? Explain. (5 points)
No. Since I am a type A my parents are either both type A or one is 0 so I could be either.
3. Select a trait of interest.
a. What is the trait? (1 point) widows peak
b. What is the phenotype for the trait? Is this the dominant or recessive allele for the trait? (2 points)
A widows peak is dominant, (B)
c. What are the possible genotypes for the parents? (2 points)
The possible genotypes would be BB or Bb
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.
B, BB, Bb
B, BB, Bb
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)
Children: XbXb, XbX, XbY, XY
Most likely there would be one color blind male and one color blind female.
5. What was the group number of the student's karyotype? What was the result of the student's karyotype? (Include the sex and the chromosomal disorder, if applicable. If there was no chromosomal disorder, the student must state that the individual was normal.) (5 points) What was the group number
6. Give an example of a situation in which it is important to create a karyotype for an individual. Explain. (5 points)
It would be important to know with recessive chromosomal disorders that could be passed down to offspring.
7. Genetically speaking, why is it important not to mate with a close relative? Explain. (5 points)
Inbreeding can cause homozygosity which increased the chances of a recessive genetic disorder occurring in offspring.
8. Does a karyotype tell all of a person's genetic characteristics? Explain. (5 points)
No but it could display information about the amount of Chromosomes which could help determine genetic diseases.
9. Why is a photograph of cells in metaphase utilized when constructing a karyotype? (5 points)
Metaphase shows traits that are beginning to form.
10. What does it mean to be a carrier of a genetic defective characteristic? When might it be important to know if one is a carrier? (5 points)
A carrier is one that has the recessive gene for a disease but they themselves do not exhibit symptoms. It is important to know for future offspring.
11. From the hemophilia procedure: (4 points)
a. What were the possible genotypes of the offspring?
XHXH, XHXh, Xhy,XHY
b. What is the probability of males having hemophilia?
c. How many females would have hemophilia?
d. How many carriers would there be? one 12. Explain why more males tend to suffer from X-linked disorders than females. (5 points)
Women have 2 X chromosomes and Males have only one.
13. The student has a friend that knows the student is taking biology, and she is confused about her blood type. Her blood type is O, but her dad is A and her mother is B. She asks the student if it is possible for her parents to have a child that is O. Explain the answer to her. (5 points)
Yes she can have a child that has an O blood type. Her parents could have been AO and BO which could pass the O blood type to her.
14. In a flower garden, the gardener has purple and white pansies. He notices that a new pansy has sprouted. When it finally flowers, the pansy is lavender. Explain how this happened. (5 points)
This is an example of incomplete dominance causing a blend of colors.
15. With a botanist friend's help, the gardener decides to cross the lavender pansy with the white pansy. Will this result in any purple pansies? Explain. (5 points)
No it will most likely cause light lavender pansies.
16. (Application) How might the information gained from this lab pertaining to human genetics be useful to a student enrolled in a healthcare related profession? (20 points)
The lab on human genetics would be particularly useful to a geneticist or a person working in a fertility clinic. The information gained on carriers was particularly interesting. With proper genetic testing we can alert these potential parents of their recessive carrying of diseases such as Spinal Muscular Atrophy and Cystic fibrosis. This genetic information could help these potential parents know the risks of their child having these disorders and could help persuade them into other routes such as adoption or to be prepared to deal with these potential disordwers.