Chapter 24 Flashcards
The location of a gene on a chromosome is called
a locus
Considering that males can have Klinefelter (XXY) syndrome, XYY, and normal XY chromosomal combinations, and females can have Turner (XO) syndrome, poly-X (XXX, XXXX), and normal XX combinations, it is obvious that
maleness results from the minimal presence of one Y chromosome.
Genes on the ___ chromosome determine if the sex of a child will be male or female.
Y
A normal male marries a color-blind woman. What percent of their female children will be color-blind?
0%
Color-blindness is inherited as an X-linked recessive trait. A male who is color-blind marries a heterozygous woman. What percent of their total children will be color-blind?
50%
A color-blind (recessive trait) woman will pass the allele to
all her children.
If a woman is a carrier for the color-blind recessive allele and her husband has normal vision, what are their chances that a son will be color-blind?
50%, since the mother is only a carrier.
Which of the following sex-linked diseases is characterized by the absence of a clotting factor?
hemophilia
What refers to the loss of a complete chromosome?
monosomy
A person who has an extra copy of a chromosome is said to have
trisomy
Generally, it is not possible to determine whether nondisjunction failed to occur in oogenesis or spermatogenesis. However, it is possible to assert that _____ resulted in nondisjunction in ____.
XYY; spermatogenesis
When homologous chromosomes fail to separate during meiosis, this is termed
nondisjunction.
An individual who has an XXY combination of sex chromosomes is said to have _____ syndrome.
Klinefelter
A person with an XO genotype is classified as having
Turner syndrome.
Which refers to the loss of a portion of a chromosome?
deletion
