Inherited Traits Lab
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Biology
Name
Make a data table, on the last page of this lab, to record how many people
have the dominant trait and how many have the recessive trait of those items
being studied (see the list below)
Write a hypothesis for each of the questions this lab will address
o Question #1: Will the class have more dominant or recessive traits?
o Question #2: Based on how sensitive or not sensitive your taste buds
are, how many of the three taste tests do you think you will be able to
taste?
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Survey the members of your group (your table) to determine how many have
the following traits, record in your data table and then add your information to
the class data table on the board
Dominant Traits (for some there are images below to assist you), if you don’t
have these traits you have the recessive trait:
o Widow’s peak – hair line comes to a point above the forehead
o Can roll tongue – tongue rolls to look like a hot dog bun
o Free ear lobe - ear lobe curves up to side of face instead of attaching
straight across
o Right handed – if you use both hands, choose the hand you usually eat
with
o Bent little finger – hold your two pinky fingers side-by-side and see if
they line up straight or bend out at the top
o Hitchhiker’s thumb – top joint of thumb bends back beyond the joint
o PTC taster – place a slip of PTC on your tongue. If you taste “paper”,
you are not a taster. If you get at strong taste, you are a taster which
is dominant.
o Clasped hands – left thumb on top – when you fold your hands, fingers
interlaced, which thumb is on top? Left thumb on top is dominant.
o Thiourea – same process as PTC but with thiourea paper
o Sodium benzoate – same process as PTC but with sodium benzoate
paper
Add your group’s data to the class data table
When all the groups have entered their data, complete your table so you have
one table with the data from the entire class
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Widow’s peak
Hitchhiker’s Thumb
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Answer the following questions (2 points each)
o (4 points) Were your hypotheses supported? Give evidence why or
why not.
o Which data were the most surprising to you and why?
o If you surveyed a larger group of individuals, how do you think our
results might change? Give one or two examples.
o Could a person have all dominant traits and no recessive traits or the
other way around?
o Closely examine the data for the three taste papers. If you are a nontaster for one chemical, what does that generally mean for the other
two tests, according to the data.
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