Download Genetics UNIT EXAM Review

Name: ___________________________________
TOC#
Genetics UNIT EXAM Review
Below are review questions for each of the 5 learning goals we have addressed during this unit. This is the
majority of the science content we covered. However, as a disclaimer it does not include EVERYTHING we
covered and does not have sample analysis questions (level 4) for each goal. So to get a 4 on the unit test for
each learning goal be sure to use all your other study tools as well.
Learning Goal A:
Students can describe what Mendel discovered through his experiments
1. Explain Mendel’s experiment and what it proved.
2. Explain Mendel’s three laws.
3. What is an allele?
4. What is a gene?
5. What is phenotype?
6. What is genotype?
7. Describe the following with words and give an example: Heterozygous, homozygous recessive,
homozygous dominant
Learning Goal B:
Students know how to predict the probable outcome of phenotypes in a genetic cross from the genotypes
of the parents by using Punnett Squares and understand their limitations.
1. Why do we use Punnett squares? What are their limitations?
2. If a male is heterozygous for Brown eyes, what two gametes can he pass on
3. Complete the following Punnett Square: For humans, brown eyes are dominant (B) over blue eyes (b). A
heterozygous brown-eyed man marries a heterozygous brown-eyed female. What are the possible
genotypes and phenotypes of the offspring? Make a Punnett square and give the genotype and
phenotypes probabilities
4. Black fur(B) in guinea pigs is dominant over white fur(b). Find the probability of an offspring in a cross
between a homozygous white and a heterozygous black guinea pig parents. Make a Punnett square and
give the genotype and phenotypes probabilities
5. Let's say that in seals, the gene for the length of the whiskers has two alleles. The dominant allele (W)
codes long whiskers & the recessive allele (w) codes for short whiskers. Cross two long-whiskered
seals, one that is homozygous dominant and one that is heterozygous?
6. The problems above address simple dominance traits. Do all traits behave this way? Why or why not?
7. Explain incomplete dominance
8. Purple (P) and white (W) flowers exhibit incomplete dominance. Make a Punnett square and give the
genotype and phenotypes probabilities of a cross between and purple flower and a white flower.
9. Explain codominance.
10. Blood types are codominant. Type A and Type B are codominant while type O is recessive. Cross a
heterozygous type A male with a homozygous type B famle. Make a Punnett square and give the
genotype and phenotypes probabilities.
11. Explain sex-linked trait.
12. Colorblindess is a sex linked recessive disorder. Cross and colorblind female with a normal seeing
male. Make a Punnett square and give the genotype and phenotypes probabilities.
13. Why do sex linked disorders occur more in men?
Learning Goal C:
Students know how fertilization leading to new combinations of alleles from the male and female
gametes relates to evolution.
1. Explain how the process of meiosis is related to this goal?
2. What is the driving force behind natural selection and evolution?
3. Why are mutations important to evolution?
4. How does the law of segregation apply to this goal?
5. Are dominant alleles more common? Why or why not?
6. If green feathers are recessive to yellow feathers, explain why green feathers may become more
common in a species over time.
Learning Goal D:
Students know how to predict the probable mode of inheritance from a pedigree diagram showing
phenotypes.
1. What does a pedigree show? Why do we create them?
2. On a Pedigree, what shape are men and women?
3. On a Pedigree, a shaded shape means what? Unshaded shape?
4. Complete a pedigree for the following information. Please include weather each person is male/female,
shaded or not shaded, their phenotype and their genotype. The ability to roll your tongue is caused by a
dominant gene (R). If you can't roll your tongue, you are a non-roller and must be homozygous recessive
(rr). A father cannot roll his tongue but a mother can. Of their four children, one daughter cannot roll
her tongue. The other daughter and both sons can roll their tongues.
5. Complete a pedigree for the following information. Please include weather each person is male/female,
shaded or not shaded, their phenotype and their genotype. Diabetes is a disorder of the pancreas in
which insulin cannot be produced or is not effective. As a result, blood sugar cannot be properly
controlled. Diabetics have a homozygous recessive genotype (dd). A father carries the recessive gene
for diabetes and a mother does not (generation 1). They have two children (generation 2), a daughter
and a son. The daughter does not suffer from diabetes and marries a man who does not carry the gene
for diabetes. They have one child, a girl who is a carrier (generation 3). The son marries a diabetic
woman and they have two boys, both who suffer from diabetes (generation 3).
Learning Goal E:
Students can explain how and why genetic disorders occur and can explain several examples.
1. Describe the basic structure of DNA
2. How is genetic variation created?
3. What are mutations? Are they good or bad?
4. How do mutations relate to evolution?
5. Explain the two types of DNA based disorders.
6. Explain how a chromosomal disorder is different than a DNA based disorder.
7. Explain what the following cause: dysfunctional genes, missing genes.
8. Explain how nondisjunction occurs and at least 3 ways it can cause a genetic mutation.
9. How many chromosomes do Humans have?
10. What is a karyotype?
11. What is the difference between what you see in a man and a woman’s karyotype?
12. How can women know for sure if their offspring will have a genetic disorder before it is born?
13. Define monosomy and trisomy and give examples of disorders from each.
14. What condition causes Down Syndrome?