Download Name: _ Per: ______ Date: Chapter 14 Test Review Describe how

Name: _____________________________________________________________ Per: _____________ Date: ________________________
Chapter 14 Test Review
1. Describe how gender is determined in humans, and what chromosomes are involved in each
gamete.
2. What are autosomes?
3. What are sex-linked genes? X-linked genes?
4. Which gender displays X-linked traits more frequently? Why?
5. What are the possible phenotypes and genotypes in the human ABO blood typing gene? Which
blood types can donate to which blood types without clotting?
6. How is a karyotype produced? What does it show?
7. What are three causes for a chromosomal disorder, and during what stages of meiosis would they
occur?
8. Describe your patient’s chromosomal disorder (cause, symptoms) and your table parner’s
patient’s disorder.
9. How could you determine if a trait is a dominant trait or a recessive trait from a pedigree? Draw
an example of each.
10. Determine as the genotypes of as many of the individuals as possible. The shaded trait is a
recessive trait.
11. Determine as the genotypes of as many of the individuals as possible. The shaded trait is an xlinked dominant trait.
12. What would be the genotype ratio for a cross between individual #10 with a male with the
recessive allele? Write out the Punnett square of the cross.
Chapter 14 Test Review Answer Key
1. Describe how gender is determined in humans, and what chromosomes are involved in each
gamete.
Father produces gametes with either X or Y chromosome, mother produces gametes with only
X chromosome. If the zygote receives a Y chromosome from father’s gamete, then it will
develop into a male embryo because of the testosterone gene on the Y chromosome.
Otherwise the embryo will develop as a female.
2. What are autosomes?
Any of the chromosomes other than the sex chromosomes (X or Y chromosome, 23rd pair)
3. What are sex-linked genes? X-linked genes?
Sex-linked genes are those found on either the X or Y chromosome. X-linked genes are found
only on the X.
4. Which gender displays X-linked traits more frequently? Why?
Males display the X-linked traits more because they only have one copy of the gene, so there is
no opportunity to be heterozygous and therefore hide the trait (as a carrier).
5. What are the possible phenotypes and genotypes in the human ABO blood typing gene? Which
blood types can donate to which blood types without clotting?
phenotype A—genotype AA or AO; phenotype B—genotype BB or BO; phenotype AB—
genotype AB; phenotype O—genotype OO
Type A blood can be donated to A or AB type recipients
Type B blood can be donated to B or AB type recipients
Type AB blood can be donated only to AB type recipients
Type O blood can be donated to A, B, AB, or O type recipients
6. How is a karyotype produced? What does it show?
A picture is taken of a cell during mitosis (when chromosomes are condensed), and the
chromosomes are arranged into homologous pairs.
7. What are three causes for a chromosomal disorder, and during what stages of meiosis would they
occur?
Non-disjunction (occurs during metaphase I/anaphase I), translocation (occurs during
crossing over during prophase I), and deletion (also occurs during crossing over during
prophase I)
8. Describe your patient’s chromosomal disorder (cause, symptoms) and your table parner’s
patient’s disorder.
See handout of chromosomal disorders from genetic counselor letter activity
9. How could you determine if a trait is a dominant trait or a recessive trait from a pedigree? Draw
an example of each.
If an offspring with a trait has two parents who do not have the trait, then the trait must be
a recessive trait.
If an offspring without a trait has two parents with the trait, then the trait must be a
dominant trait.
10. Determine as the genotypes of as many of the individuals as possible. The shaded trait is a
recessive trait.
11. Determine as the genotypes of as many of the individuals as possible. The shaded trait is an xlinked dominant trait.
1. XRXr 2. XrY 3. XRY 4. XRXr 5. XrY 6. XrXr 7. XRY 8. XRXr 9. XrY 10. XRXr 11. XrY
12. What would be the genotype ratio for a cross between individual #10 with a male with the
recessive allele?
Mother--XRXr Father--XrY
Xr
Y
XR
XR Xr
XR Y
Genotype Ratio—1 XRY : 1 XrY : 1 XRXr : 1 XrXr
Xr
Xr Xr
Xr Y