Practice Quiz for General Genetics
Chapter 4 -- Sex Determination and Sex-linked Characteristis
Chapter 6 -- Pedigree Analysis and Applications
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1. In fruit flies, the gene that is called the sex-switch gene is
A. doublesex
B. zinc finger gene
C. sex lethal
D. songless

2. If 83 individuals are homozygous for the recessive trait, eyeless, and 67 of those individuals are eyeless, then this is an example of
A. expressivity
B. pleiotropy
C. incomplete penetrance
D. incomplete dominance

3. Which of the following concepts is attributable to Sutton and Boveri?
A. one allele may be dominant to another allele at the same locus
B. chromosomes are the carriers of the genes
C. genetic traits are particulate in nature
D. the pair of alleles at a locus separate from each other during gamete formation

4. If an affected male has affected daughters and sons in about the same number as unaffected daughters and sons, the trait is likely to be an
A. X-linked dominant trait
B. autosomal recessive trait
C. autosomal dominant trait
D. X-linked recessive trait

5. Breast development in mammals is typically only seen in females and the trait is inherited on the autosomes. This is an example of a
A. Y-linked trait
B. X-linked trait
C. sex-influenced trait
D. sex-limited trait

6. In birds with a ZW sex determining mechanisms, males are
A. cytogametic
B. homogametic
C. heterogametic
D. pleiogametic

7. The theory that the Barr Body is an inactivated X-chromosome is
A. the cell theory
B. the Lyon hypothesis
C. the chromosome theory of inheritance
D. the genic balance theory

8. In mammals, the locus on the Y chromosome that is necessary for a zygote to become male is
A. the sex-determining region Y
B. the ovary suppression factor
C. the histocompatibility Y-antigen
D. the ZFY gene

9. If an affected male has all affected daughters but no affected sons, the trait is likely to be an
A. X-linked dominant trait
B. autosomal recessive trait
C. autosomal dominant trait
D. X-linked recessive trait

10. Dosage compensation of the X chromosome in fruit flies is by
A. the formation of Barr bodies in females
B. the formation of Barr bodies in males
C. hyperactivity of the X chromosome in males
D. reduced activity of the autosomes in males

11. Human males are neither heterozygous nor homozygous for alleles on the X chromosome, they are
A. hemizygous
B. heterozygous
C. homogametic
D. dominant

12. The crosses involving the white-eyed and red-eyed alleles on the X chromosome in fruit flies proved to be a test of the
A. Cell Theory
B. Lyon Hypothesis
C. Chromosome Theory of Inheritance
D. Rule of Segregation

13. For loci carried on the X chromosome, the reciprocal crosses will
A. always give the same phenotypic ratio among the offspring in the F1 and F2 generations
B. sometimes give the same phenotypic ratio among the offspring in the F1 and F2 generations
C. always give different phenotypic ratios among the offspring in the F1 and F2 generations
D. will sometimes give different phenotypic ratio among the offspring in the F1 and F2 generations

14. In humans, many more males are affected by Duchene muscular dystrophy than females and these affected males typically come from unaffected parents. The likely inheritance pattern is
A. autosomal dominant
B. autosomal recessive
C. X-linked dominant
D. X-linked recessive

15. Based on the genic balance theory, you would predict that a human with XXY sex chromosomes and a normal number of autosomes would be
A. female
B. male
C. intersex
D. metafemale

Last updated on 7 September 2004.
Provide comments to Dwight Moore at mooredwi@emporia.edu.
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