General ---------Biology----------------------------------------------------- ------------------Online------------------------------------------------------------------------------------------------------------------------------ Quiz Ch. 15 Chromosomal Basis of Inheritance Revised March 11, 2005

Some questions refer to images that require you click on a hyperlink to see.

  1. If inheritance of a human trait is sex-linked (on the X chromosome)
     and recessive, any of the following could result EXCEPT that
     a. expression of the trait might "skip" a generation.
     b. the trait could be more common in females than males.
     c. all females might become homozygous for the trait.
     d. the gene for the trait might mutate to a dominant allele.
     e. females could be a mosaic of two cell types.

  2. Which of these chromosome alterations is best described as a gene duplication?
Click on link above to see Figure.
     a. 
     b. 
     c. 
     d. 
     e. 

 3. What do all males inherit from their mother?
     a. mitochondrial DNA
     b. X chromosome
     c. male-pattern baldness trait
     d. mitochondrial DNA and X chromosome
     e. mitochondria DNA, X chromosome, and male-pattern baldness trait

4. What does independent assortment refer to?
     a. the replication of each DNA thread independently during the S Phase
     b. the random arrangement of chromosomal tetrads at metaphase I
     c. the separation of chromatids at anaphase II
     d. the random arrangement of gene loci on a chromosome
     e. the fact that any pair of chromatids in a tetrad can cross over

 5. A Barr body is normally found in the nucleus of which kind of human
     cell?
     a. unfertilized egg cells only
     b. sperm cells only
     c. somatic cells of a female only
     d. somatic cells of a male only
     e. both male and female somatic cells

 6. The particular position of a gene on a chromosome is known as a(n)
     a. allele.
     b. tetrad.
     c. chiasma.
     d. locus.
     e. map distance.

7. The frequency of crossing over between any two linked genes is
     a. more likely if they are recessive.
     b. difficult to predict.
     c. determined by their relative dominance.
     d. the same as if they were not linked.
     e. greater the further apart they are.

 8. A recessive allele on the X chromosome is responsible for red-green
     color blindness in humans. A normal vision woman whose father is
     color-blind marries a color-blind male. What is the probability that
     this couple's son will be color-blind?
     a. 0%
     b. 25%
     c. 50%
     d. 75%
     e. 100%

 9. A man who carries an X-linked allele will pass it on to
     a. all of his daughters.
     b. half of his daughters.
     c. all of his sons.
     d. half of his sons.
     e. all of his children.

 10. In cats, black color is caused by an X-linked allele; the other
     allele at this locus causes orange color. The heterozygote is
     tortoise-shell. What kinds of offspring would you expect from the
     cross of a black female and an orange male?
     a. tortoise-shell female; tortoise-shell male
     b. black female; orange male
     c. orange female; orange male
     d. tortoise-shell female; black male
     e. orange female; black male

                       ---------------OMIT 11, 12, 13---------------
 Use the information below to answer the following question(s).
 An achondroplastic dwarf man (heterozygous) with normal vision marries a
 color-blind woman of normal height. The man's father was 6 feet
 tall, and both the woman's parents were of average height.
 Achondroplastic dwarfism is autosomal dominant (i.e. like Brown Eyes), and red-green color
 blindness is X-linked recessive.  Hint:  first, write out all possible genotypes and
phenotypes for each trait, then write out the genotypes of each parent, then do seperate 
Punnett squares for each trait, and then multiply the probabilities.

 11. How many of their female children might be expected to be
     color-blind dwarfs?
     a. all
     b. none
     c. half
     d. one out of four
     e. three out of four

 12. How many of their male children would be color-blind and normal
     height?
     a. all
     b. none
     c. half
     d. one out of four
     e. three out of four

 13. They have a daughter who is a dwarf with normal color vision. What
     is the probability that she is heterozygous for both genes?
     a. 0
     b. 0.25
     c. 0.50
     d. 0.75
     e. 1.00

 14. If a human interphase nucleus contained three Barr bodies it can be
     assumed that the person
     a. has a normal female genotype.
     b. is a male.
     c. must have 4 X chromosomes.
     d. has Turner syndrome.
     e. has Down syndrome.

15. If a karyotype shows an individuals with the XXY genotype, then the
individual is most likely
     a. a normal female
     b. a normal male.
     c. an individual with Kleinefelter syndrome.
     d. an individual with Turner syndrome.
     e. a meta-female.

 16. The diploid chromosome number in honeybees is 32. What is the number
     of chromosomes in the somatic cells of a male honeybee?
     a. 4
     b. 8
     c. 16
     d. 32
     e. 64

 17. A collection of Cassette tapes or compact disks contains a series of distinct pieces
     of electrical or physical information that are interpreted by a tape
     player or compact disk player, resulting in music. If the
     information that produces a song is analogous to a gene, and the
     tape or compact disk is analogous to a chromosome, then "linked
     genes" are analogous to
     a. the length of the songs on the tape or disk.
     b. songs on the same tape or disk.
     c. the volume of the music on the tape or disk.
     d. the tempo of the music on the tape or disk.
     e. the informational content of the songs on the tape or disk.

 18. The following figure shows five genes on a pair of duplicated chromosomes.
The paternal version is shown in black, maternal in red.  Crossing over frequently occurs 
between maternal and paternal versions of chromosomes during meiosis.

Between which two genes would you expect the highest frequency of
recombination? Stated another way, if crossing over occurs between the black strand and
the red strand during meiosis, which two linked-genes are most likely to wind up 
separated by crossing over?
     a. 1  and  3
     b. 1  and  2
     c. 2  and  4
     d. 3  and  4
     e. 1  and  4

 19. The karyotype of a Down syndrome individual will show

a.  trisomy of the X chromosome
b.  cells that are monosomic for chromosome 22
c.  trisomy of chromosome 21
d.  XXY
e.  trisomy of chromosome 17