WorksheetsIB Sex-Linked & Pedigrees
Total questions: 25
Worksheet time: 2hrs 37mins
Orange or black fur is a single, X-linked, co-dominant trait in cats. Calico cats have white fur with patches of orange and black. Is it true that calico cats can only be female?
Yes, because they have 2 'X' chromosomes, and therefore can have both the orange and black alleles (XO XB)
No, males can be calico because they can have both the alleles for orange and black (XO YB)
Yes because the trait is found on the X chromosome (XOB X)
No, males can be calico because the trait is found on the X chromosome (XOB Y)
What is NOT a possible genotype for someone with type B blood?
IBIB
IAIB
IB i
iIB
Colorblindness is more common in males than in females because......
fathers pass the allele for colorblindness to their sons only
the allele for colorblindness is located on the Y chromosome
the allele for colorblindness is recessive and located on the X chromosome
males who are colorblind have two copies of the allele for colorblindness
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%
Hemophilia is a recessive X-linked disorder. According to the Punnett square, which is NOT true?
50% of all offspring will have the disorder
50% of male offspring will not have the disorder
25% of female offsprings will have the disorder
the mother does not have the disorder but is a carrier
Bob is blood Type B and Hilda is Type A, their son Barry is Type O. What are the only possible genotypes of Bob and Hilda?
Bob: IBi
Hilda: IAi
Bob: IBi
Hilda: IAIA
Bob: IBIB
Hilda: IAi
Bob: IBIA
Hilda: IAi
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
What do we use pedigrees for?
To look at families
To make determinations about the offspring
To track traits in families
To find out what type of dog we have
In a pedigree, what is the symbol for an Affected Male (a male with the condition)?
Half Circle
Half Square
Full Shaded Circle
Full Shaded Square
Which best explains why individual IV-7 has colorblindness?
Because her mom is a carrier and her dad has the gene
Because her dad has it.
Because her siblings have it.
Because her uncle has it.
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
