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WorksheetsSex-linked and Pedigrees
Total questions: 15
Worksheet time: 41mins
Colorblindness is a recessive X-linked disorder.
Which genotype represents a male with normal vision?
XN YN
Xn Yn
XN Y
Xn Y
Duchenne muscular dystrophy is a recessive X-linked disorder.
According to the Punnett square, what percentage of offspring will have the disorder?
0%
25%
50%
100%
Males are more likely to suffer from a sex-linked disease or disorder because...
males are the weaker sex
males have less DNA
males have 1 X chromosome, so the disorder is more likely to be expressed
females are the stronger sex
Give the genotype for person II-1, for this autosomal trait.
GG
Gg
gg
we cannot be 100% sure of the genotype
If hemophilia is a sex-linked recessive trait, what genotype would individual III-3 have?
XhX
XhXh
XhYh
XhY
If this pedigree shows a recessive disorder, what MUST the genotype of individual 4 be?
HH
Hh
hh
This trait is
autosomal recessive.
sex-linked recessive.
autosomal dominant.
Color blindness is carried by the X chromosome.
A mother is a carrier of color blindness. Her husband has normal vision.
The probability of having a color blind offspring is (a) percent.
In a cross between a pure red eyed female and a white eyed male, what would the genotypes of the parents be?
XRXr with XR Y
XRXr with Xr Y
XRXR with XR Y
XRXR with Xr Y
XrXr with Xr Y
Look at this cross: XB XB x Xb Y
What proportion/percent of the male children are colorblind?
100%
75%
25%
0%
Look at this cross: XBXb x XBY
What proportion of the male children are colorblind?
100%
75%
50%
25%
H= normal blood clotting
h=hemophilia
XHXh x XHY
What is the probability that any of their offspring will have hemophilia?
4/4
3/4
2/4
1/4
