Download BY 123 SI Session #9 Chapter 15 Siby123.yolasite.com Terms to

BY 123 SI Session #9
Chapter 15
Siby123.yolasite.com
Terms to Know:
1) Wildtype:
2) Mutant phenotype:
3) Chromosome theory of inheritance:
4) Sex-linked genes
5) Linked genes:
6) Polyploidy:
7) Nondisjunction:
Chapter 42: Human Gametogenesis
1) Spermatogenesis:
a)
b)
c)
d)
What is the chromosome number of spermatogonium?
What is the chromosome number of the primary spermatocyte?
What is the chromosome number of the secondary spermatocyte?
What is the chromosome number of sperm cell?
2) Oogenesis:
a) What is the chromosome number of oogonium?
b) What is the chromosome number of the primary oocyte?
c) What is the chromosome number of the secondary oocyte and the fertilized egg?
d) How many polar bodies are released before the fertilized egg?
Section 15.3
1) In a test cross between a heterozygote tall, purple-flowered pea plant and a dwarf, whiteflowered plant:
a) What are the phenotypes of offspring that are parental types?
b) What are the phenotypes of offspring that are recombinants?
2)
The following recombination frequencies have been determined for several gene pairs. Draw a
gene and show the distance between each loci.
J and K: 12%
J and M : 9%
K and L : 6 %
L and M : 15%
3) In guinea pigs, black (B) is dominant to brown (b), and solid color (S) is dominant to spotted (s).
A heterozygous black, solid-colored guinea pig is mated with a brown, spotted guinea pig. The
offspring from several litters are as follows: black solid: 16; black spotted: 5; brown solid: 5; and
brown spotted: 14. Are these genes linked or unlinked? If they are linked, how far apart are
they?
Section 15.4
1) Two nonhomologous chromosomes have gene orders of A-B-C-D-E-F-G-H-I-J and
M-N-O-P-Q-R-S-T . What types of chromosome alterations would have occurred if daughter
cells were found to have a gene sequence of A-B-C-O-P-Q-J-I-H on the first chromosome?
2) A chromosome has a gene order of A-B-C-D-E-F. After meiosis, the chromosome has a gene
order of A-F-E-D-B-C. What type of alterations would this be?
Multiple Choice:
1) In which of the following structures would you expect to find a bar body?
a) An egg
b) A sperm
c) A liver cell of a man
d) A liver cell of a woman
e) A mitochondria
2) When we say that a few of the genes for Mendel’s pea characters were physically linked but
genetically unlinked, we mean that:
a. The genes are on the same chromosome, but they are more than 50 map units (50%) apart.
b. The genes assort independently even though the chromosomes they are on travel to the
metaphase plate together
c. Their alleles segregate in anaphase I, and each gamete receives a single allele for all of these
genes
d. Dihybrid crosses with these genes produce more than 50% recombinant offspring even
though they are on the same chromosome
e. Mendel could not determine that the genes were on the same chromosome because he did
not perform crosses with these gene pairs.
3) A mutation in a mitochondrial gene has been linked to a rare muscle-wasting disease in humans.
This disease is:
a. Found more often in males than in females
b. Found more often in females than in males
c. Inherited in a simple Mendelian fashion
d. Caused by a translocation of a nuclear gene to the mitochondria
e. Inherited from the mother and is equally likely to occur in male and female offspring.