Genetics Worksheet SCI/230 Version 7: Punnett Square

Genetics Worksheet SCI/230 Version 7: Punnett Square

Genetics Worksheet
SCI/230 Version 7

1

Associate Program Material
Genetics Worksheet
Review the images below and answer the follow-up questions.

Key:
Pedigree showing inheritance of cystic fibrosis

male affected with cystic fibrosis
unaffected male

Generation

female affected with cystic fibrosis
unaffected female

I

II

III

IV
A

Pedigree showing Inheritance of Huntington’s Disease

V

Questions:

Key:
male with Huntington’s Disease
unaffected male

Generation 1. According to the pedigree, is cystic fibrosis inherited as a dominant oremalerecessive trait?
f as a with Huntington’s Disease
Explain how you made your conclusion using evidence from the pedigree and the principles
of genetics.
unaffected female
I
2. What would a Punnett square that shows how the son in generation IV (marked with an A)
inherited cystic fibrosis look like?
II

III

IV

V

Genetics Worksheet
SCI/230 Version 7

2

Key:
Pedigree showing inheritance of Huntington’s disease

male with Huntington’s disease
unaffected male

Generation

female with Huntington’s disease
unaffected female

I

B

II

III

IV

V
Questions:
1. According to the pedigree, is Huntington’s disease inherited as a dominant or as a recessive
trait? Explain how you made your conclusion using evidence from the pedigree and the
principles of genetics.
Key:

Pedigree showing Inheritance of Huntington’s Disease
2. What would a Punnett square that shows how the first daughter in generation IIHuntington’s Disease
male with (marked with
a B) did not inherit Huntington’s disease look like?

unaffected male
3. What is the role of chromosomes in the inheritance of genetic traits, such as cystic fibrosis
Generation
and Huntington’s disease?
female with Huntington’s Disease
I

II

III

IV

V

unaffected female