Quiz Ch 9 BILD – Flashcards
Unlock all answers in this set
Unlock answersquestion
What do hemophilia, Duchenne muscular dystrophy, and red-green color blindness have in common?
answer
they are x linked
question
If a daughter expresses an X-linked recessive gene, she probably inherited the trait from:
answer
both parents
question
A woman who does not carry the color-blindness allele has children with a man who is color blind. What proportion of their children will be color blind?
answer
none
question
Regarding the human sex chromosomes, which statement is correct?
-The X chromosome carries the genes for the development of male phenotype.
-X and Y are different in size but carry nearly equal numbers of genes.
-The Y chromosome carries a greater number of genes than does the X chromosome.
-The X chromosome carries only gender-related genes.
-The X chromosome carries more genes than does the Y chromosome.
answer
The X chromosome carries more genes than does the Y chromosome.
question
A study of several pedigrees demonstrates that two parents are normal. If some of their children express a trait, then the trait is controlled by a:
answer
recessive gene
question
In a pedigree chart, a darkened square demonstrates a:
answer
diseased male
question
What is a recessive disorder?
answer
a genetic disorder that will express itself in the presence of two recessive alleles
question
A trait such as albinism is seen with equal frequency in males and females. Two people who do not have the trait might have offspring who do have the trait, at a frequency of approximately one in four. What can you conclude about the inheritance of this trait?
answer
recessive, autosomal
question
The % of recombinants in a cross examining 2 linked genes can never be 51%.
answer
True
question
______ genes violate Mendel's principle of independent assortment.
answer
Linked
question
A woman who is a carrier for the hemophilia gene has a child with a man who does not have hemophilia. Which prediction is correct?
-All of the sons and none of the daughters will have hemophilia.
-Half of the sons and none of the daughters will have hemophilia.
-Half of the sons and half of the daughters will have hemophilia.
-Half of the daughters and none of the sons will have hemophilia.
-All of the daughters and none of the sons will have hemophilia.
answer
Half of the sons and none of the daughters will have hemophilia.
question
Why do X-linked conditions appear more frequently in males than in females?
answer
A male with a nonfunctioning allele on the X chromosome does not have another allele of that gene on the Y chromosome that could cover up the nonfunctioning one.
question
The human genome has how many pairs of autosomal chromosomes?
answer
22 pairs
question
The recombination frequency between gene B and gene C is 11%. The recombination frequency between gene B and gene D is 5%. The recombination frequency between gene C and gene D is 15%. What would be the arrangement of these genes on a linkage map?
answer
DBC
question
A dihybrid cross produces 30 recombinant offspring out of a total of 1,000 offspring. What is the recombination frequency of the two gene pairs?
answer
3%
