Download Notes Intro to Genetics

Biology
Unit 8: Meiosis and Genetics
Name__________________________
Date____________________Per____
Notes 3: Intro to Genetics
Genetics
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The ______________________________
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______________________ is the _____________________________________ from parents to their offspring.
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Gregor ______________________was a monk who studied genetics by observing and experimenting with pea
plants (1857-1865).
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Known as the __________________________________________________.
What information do our chromosomes hold?
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Genes that code for ________________ that __________________ our individual ________________.
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For example: Ear hair, Hair color, eye color, ear lobes, hair line, hitch hiker thumb, tongue rolling, behavior,
predisposition for disease, etc.
Mendel’s Experiments
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Cross pollinated pure plants with contrasting traits.
P- _______________ generation
F1 – __________ generation of offspring
F2 = F1 crossed with F1 to get _______________
generation of offspring.
Genetic Expression
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________________= inherited __________________________ that are expressed.
Ex. Widows peak vs. straight hairline
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Alleles = ___________________________________________________________ (you get one from mom and
one from dad).
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We use capital letters and lower case letters to note if they are a dominant allele or a recessive allele.
W = _________________________ (Widows peak)
w = _________________________ (straight hairline)
Law of Dominance
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When different alleles for a characteristic are inherited, the ___________ of only one (the ______________one)
will be _____________________.
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______________________________________________ the expression of ____________________________
allele traits.
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Examples:
– Person 1 inherited WW from each parent, so this person has a widows peak
– Person 2 inherited Ww from each parent, so this person has a widows peak (the dominant allele
masked the recessive allele, so this person carries the allele for straight hair and can pass it on to the
offspring.
– Person 3 inherited ww from each parent, so this person has a straight hairline.
Determining Genotypes and Phenotypes
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__________________________ – the ________________________ of an organism (___________ combinations)
Ex: WW – _________________________________________________ (widow’s peak)
Ww – ___________________________________ (widow’s peak)
ww - __________________________________________________ (straight hairline)
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__________________________ – the external ___________________ of an organism (physical gene expression)
Ex: the person has a widows peak or they don’t.
Punnett Square
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a diagram to ___________________________________________ of an offspring _________________________
_________________________________.
Example:
Trait: Plant ________________________
Alleles: ___________________________
Mendel’s plants:
Cross: __________________________________
_________ x
_________