Transcript Welcome to Science

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Weird True & Freaky: Animal Planet
 Today’s Schedule
 1. Video of the Day
 2. Probability & Genetics
 3. Assignment
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You are going to flip your coin 20 times.
Predict how many times the coin will be “heads up”
and “tails up”
Record the results of each flip.
Probability- the likelihood that a particular event
will occur.
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What is the probability that a coin tossed 1 time
will land “heads up”?
The probability would be: 1 in 2 or 50%
What is the probability that a coin tossed 20 times
will land “heads up”?
We would expect it to be 10 in 20 or 50%
But, this is not always the case. We might have
12 in 20, 15 in 20, or maybe 7 in 20.
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Mendel recognized that the principles of
probability could be used to predict the results of
genetic crosses.
What is the probability
that the hybrid pea plants
would be tall?
3 in 4 or 75%
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How do we predict genetics?
Punnet Square- a chart that
shows all the possible
combinations of alleles that
can result from a genetic
cross.
Punnet Squares help
scientists predict the
outcome of a genetic cross.
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Phenotype- an organisms physical appearance, or
its visible traits
Genotype- an organisms genetic makeup or allele
combinations
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Homozygous- an organism that has two identical
alleles for a trait. (homo = same)
Heterozygous- an organism that has two different
alleles for a trait (hetero = different)
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What happens when two organisms reproduce and
there is not a dominant or recessive allele?
Both alleles will be expressed in the offspring.
Codominance- neither allele is dominant or
recessive
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Punnett Squares
Drag-and-Drop Genetics: Monohybrid
Punnetsquares
punnet square interactive
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Making predictions is an important part of science.
An accurate prediction can be a sign that you
understand the event you are studying. In this lab
you will make predictions as you model the events
involved in genetic crosses.
Problem: How can you predict the possible results
of genetic crosses?
Materials: 2 Paper Bags, 2 red beans and 2 white
beans
Data Table 1
Trial Allele From Bag 1 Allele From Bag 2
(Female Parent)
(Male Parent)
1
2
3
4
5
6
Offspring’s
Alleles