Bio Homework Lab
Genetics Review
This assignment will make up for the two genetic labs that we would of done if we were meeting face to face. I will have you do various things to help you grasp the material. We would of done A LOT of Punnett squares in lab. If you are having trouble please contact me.
1. Match the correct definition to the term in the table below. Type the letter in the table.
A. Alternative form of a gene, located at a specific point on chromosome. (DNA coding that will determine distinct traits)
B. Having two identical alleles for a given gene
C. A unit of hereditary information with a specific sequence in DNA.
D. Having two different alleles for a given gene.
E. Breeding an organism of an unknown genotype with an organism with a homozygous recessive genotype. The offspring phenotype will determine the unknown genotype.
F. The genetic makeup or set of alleles of an organism
G. Allele’s phenotypic effect is not observed in a heterozygote
H. Allele’s phenotypic effect is fully expressed in a heterozygote
I. A cross done to determine if a gene is located on an autosome or sex-chromosome.
J. The physical traits of an organism determined by genetic makeup.
Term | Definition Letter |
Gene | |
Allele | |
Genotype | |
Phenotype | |
Homozygous | |
Heterozygous | |
Recessive Allele | |
Dominant Allele | |
Test Cross | |
Reciprocal cross |
Star Wars Genetics – Monohybrid Crosses
Watch the following video to review on Monohybrid crosses.
https://www.youtube.com/watch?v=i-0rSv6oxSY
Geneticists at Endor have been investigating the genetic makeup of the organisms in this community. You will work through a few problems to help them out.
2. Brown body color (B) is dominant to red (b). Chewbacca recently met Susiebacca at a dance. They don’t have to worry about social distancing there right now. Chewbacca is heterozygous for his brown hair, but Susiebacca has red hair. Fill in the Punnett square below to see the possibilities if the night went well and they were to have children.
On the table below type in your answers. The black square will be left open. The parental gametes will be in the gray squares. There should only be one letter in each of these squares. The white squares are the possible kids. There will be two letters in those squares. Use this info for each time you see this type of table. Be sure to answer all of the questions. Some have two parts.
a. What are the possible genotypes for their children? What is the ratio?
b. What are the possible phenotypes for their children? What is the ratio?
3. Everyone in Anakin Skywalker’s family has “The Force” (A) which is determined by the amount of metacholorian in the body. Having “The Force” is a dominant trait. His family brags that they are a “purebred” line. He recently married a nice girl, Amidala, who does not possess “The Force” (a). Create a punnett square to show the possibilities that would result if Anakin and his new bride had children.
a. What are the chances of a child with “The Force”?
b. What are the chances of a child without “The Force”?
c. Would Anakin’s children still be considered purebreds? Explain.
4. Wicket W. Warrick, general of the Ewoks and his wife recently had a Lil’ Ewok. However… this has not been a happy occasion for them. Mrs. Warrick has been upset since she first saw her new baby who has stripes. She claims the hospital goofed and mixed up her baby with someone else’s baby. Mr. Warrick is homozygous for his solid-colored fur, while his wife is heterozygous for her solid-colored fur. Solid (A) is dominant to stripes (a) in fur. Do the Punnett square to see if the hospital messed up.
a. List the possible genotypes of their kids. What is the ratio?
b. List the possible phenotypes of their kids. What is the ratio?
c. Did the hospital mess this one up or is it possible that it is their kid? Explain.
Dihybrid Problem (only one I promise)
Watch this video to remind yourself about dihybrid crosses.
https://www.youtube.com/watch?v=qIGXTJLrLf8
5. In horses, the coat color black is dominant (B) over chestnut (b). The trotting gait is dominant (A) over the pacing gait (a). If a homozygous black pacer is mated to a homozygous chestnut, heterozygous trotter.
In this table you will not have anything in the black square. The parental genotypes will be in the gray squares. You will have two letters in each gray square. The potential babies are going to be in the white squares. There will be four letters in those squares.
a. What are the parental genotypes?
a.
b.
b. What are the gamete combinations you got from the FOIL method for both parents?
a.
b.
c. What are the genotypes of the offspring and the ratio?
d. What are the phenotypes of the offspring and the ratio?
Sex-Linked Problems
Watch the following video to review yourself on sex-linked traits.
https://www.youtube.com/watch?v=h2xufrHWG3E
Be careful when answering these questions. They will be asking things specific to gender. Remember that Sex-linked problems tell us both the gender and the genotype/phenotype.
6. In humans, hemophilia is a sex-linked recessive trait on the X chromosome. If a female who is a carrier for hemophilia marries a male with normal blood clotting, answer the following questions.
a. What fraction of the female children will have hemophilia?
b. What fraction of the female children will be carriers?
c. What fraction of the male children will have normal blood clotting?
d. What fraction of the male children will have hemophilia?
7. Color-blindness is a sex-linked recessive trait on the X chromosome. Two normal vision parents have a color-blind son.
a. What are the genotypes of the parents?
b. What fraction of the male children will be color-blind?
c. What fraction of the female children be carriers?
d. What fraction of the female children will be color-blind?
Blood Typing Problems
Watch the video to review yourself on blood typing.
https://www.youtube.com/watch?v=9O5JQqlngFY
8. Suppose a father and mother claim they have been given the wrong baby at the hospital. They must have been at the same hospital the Ewoks were at. Both parents are blood type A. The baby they have been given is blood type O.
Is it possible it is their kid? Work out the Punnett square and explain your reasoning.