Download genetic note sheet 2014 2 pages

Name ______________________
Period____________
Classical Genetics Part I
Genotypes and Phenotypes Notesheet
Gregor Mendel was ________________________________________________________________________
__________________________________________________________________________________________
Genetics: _________________________________________________________________________________
Heredity is ________________________________________________________________________________
__________________________________________________________________________________________
Mendel Studied Pea Plants
It seemed to Mendel that one of the types was_________________ over the other____________________ type.
We call an individual type of gene a(n) ________________.
Dominant and Recessive Alleles
Individual Alleles control the inheritance of traits.
Some alleles are _______________, while other alleles are _______________
Dominant Allele: __________________________________________________________________________
__________________________________________________________________________________________
Recessive Allele: ___________________________________________________________________________
__________________________________________________________________________________________
Important Points:
•
For a dominant allele, we can use a ______________letter. Usually the first letter of the dominant type.
•
Example: tall = T
•
For a recessive allele, we can use a _________________ letter (but use the same letter!).
•
Example: short = t
A parent can have three possible combinations
_________, _________, or ________
What do the letters stand for?
The combination of alleles is called the_______________________. (GEN = genes)
How do these traits look?
The trait that actually physically appears is called the _______________. (PH = physical)
•
If a plant has the alleles TT, its phenotype is ______________.
•
If a plant has the alleles tt, its phenotype is ________________.
If a plant has one dominant and one recessive gene, only the _______________ gene will be expressed.
•
Remember, tall was dominant over short. So…….
•
A plant with the alleles Tt will be _____________.
1) Fill in the possible phenotypes.
Genotype Phenotype
Genotypes are the genetic make-up of an organism, what alleles it has.
TT
Phenotypes are what type of a trait is physically expressed.
tt
Tt
Genotype
2) For seed shape, round is dominant, wrinkled is recessive.
Phenotype
RR
Fill in the letter we can use for each allele.
rr
Round = ______
Wrinkled = ______
Rr
3) See if you can fill in the chart.
4) Complete the chart using letters for alleles. Use the first letter of the dominant trait.
Trait
Dominant
Recessive
Flower color
Purple =
White =
Flower position
Axial =
Terminal =
Seed color
Yellow =
Green =
Seed shape
Round =
Wrinkled =
Pod shape
Full =
Flat =
Pod color
Green =
Yellow =
Tall =
Short =
Height
Homozygous dominant ______________________________________________________Example:_______
Homozygous recessive ______________________________________________________Example: _______
Heterozygous ______________________________________________ Example: ______(Put the capital first)
Genotype Phenotype
5) Round peas are dominant, wrinkled peas are recessive.
Homozygous
dominant
Homozygous
recessive
Heterozygous
6) Tall pea plants are dominant, short pea plants are recessive.
Genotype Phenotype
Homozygous
dominant
Homozygous
recessive
Heterozygous
7) Purple pea flowers are dominant, white pea flowers are recessive.
Genotype Phenotype
Homozygous
dominant
Homozygous
recessive
Heterozygous
8) Yellow peas are dominant, green peas are recessive.
Genotype Phenotype
Homozygous
dominant
Homozygous
recessive
Heterozygous
Genotype Phenotype
9) Full pea pods are dominant, flat pea pods are recessive.
Homozygous
dominant
Homozygous
recessive
Heterozygous