Download mendelian genetics guided notes

Mendelian Genetics Notes
What determines which characteristics we inherit from our biological parents?
Heredity is what determines the characteristics that we inherit from our biological parents.
Heredity is the passing on of characteristics from parents to offspring. The study of heredity is
called Genetics. The father of Genetics is Gregor Mendel. He was the first to succeed in
predicting how traits would be transferred from one generation to the next.
Activating Strategy:
 Eye color from mom
 Height from my dad
 Hair color from my mom
 Forehead from my dad
 Facial structure from my dad
Heredity = the passing on of characteristics from parents to offspring
Genetics = the study of heredity
Mendel
 the __father of genetics_______________________________________

lived in ___Austria around 1822_________

studied __pea plants_______________________

first to succeed __in predicting how traits would be transferred from one generation to
the next_____________________________
1. Rule of Unit Factors – each organism has 2 alleles that control each trait
Ex. 1 allele comes from mom and 1 allele comes from dad
2. Rule of Dominance – In cases in which 2 or more alleles for a single trait exist, one
allele may be dominant (mask) to the recessive one
Ex. Dominant = TT or Tt
Recessive = tt
3. Law of Segregation – each gamete receives 1 allele, during fertilization the gametes
randomly pair resulting in 4 possible combinations
Ex.
4. Law of Independent Assortment- the genes for different traits separate into gametes
independently of each other
Ex. Genes for seed shape and seed color are inherited independently of each other
1.
2.
3.
4.
Use same letter for different alleles of __one gene______________.
Use an uppercase letter for the ___dominant____________ allele
Use a lowercase letter for the ____recessive________________ allele
Always write the ___dominant______________ allele first
Genotype = the genetic make-up (Ex. TT, Tt, or tt)
Phenotype = what it looks like, physical appearance (tall or short)
Homozygous genotype 2 alleles are the same
Ex. TT or tt
Heterozygous genotype 2 alleles are different
Ex. Tt
Assessment Prompt:
1. Determine if the following are genotypes or phenotypes.
LL ___Genetype____________
Blond hair __phenotype_______
Dimpled chin __phenotype_____
Dd __Genotype_____________
2. G = green pea pod
g = yellow pea pod
Determine the phenotype and label homozygous or heterozygous.
Homozygous or
Genotype
Phenotype
Heterozygous
Gg
Green
Heterozygous
GG
Green
Homozygous
gg
Yellow
Homozygous