Contributed by: The State University of New York
The State Education Department, Albany, New York (NYSED)
1996 Administration
Task: In this task you will analyze genetic characteristics
from a family tree.
Directions
Part I
Based your answers to the following questions on the pedigree
chart below and on your knowledge of biology. The pedigree traces
the expression of a particular trait, represented by the darkened
symbol, through three (3) generations. These generations are labeled
Patent Generation, F1, and F2 so that the correspond to the generations
of pea plans that Gregor Mendel used to formulate his Laws of Heredity.
Answer sheet
Part 1 - Human Inheritance
- Is the trait represented by the darkened symbol dominant or
recessive?
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- Using complete sentences describe how Mendel would have explained
your answer to question #1?
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- Describe all the possible genotypes of Bernie, his mother, his
father, and his brother, Al.
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- Using complete sentences explain how you determined your answer
to question #3.
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Part II
Directions:
Base your answers to the following questions on the pedigree chart
below and on your knowledge of biology. The pedigree traces the
expression of a particular trait, represented by the darkened symbols,
through three (3) generations. Studies have shown that individuals
with this trait are frequently male. The trait rarely appears in
females and only if the father also has the trait.
- Is the gene for this trait dominant or recessive?
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- Is the gene for this trait carried on the X or Y chromosome?
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- Using complete sentences explain why the trait is more common
in males than in females.
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- Using coded symbols give the genotypes of the following family
members?
Be sure to include your symbol for representing the genotypes
you describe.
Symbols -
- Bruce - ________________________________
- Bruce's Father - ________________________________
- Bruce's Mother - ________________________________
- Mary - ________________________________
- If Doug marries a woman whose lacking the trait, but whose father
has the trait, what is the probability that they will have a son
with the trait? What is the probability of their daughters having
the trait?
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NYS Alternative Assessment in Science Project
NSF Grant #MDR-9154506
Copyright, April 1996
The State University of New York
The State Education Department
Albany, New York 12234
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