Chapter 11.2 (Pg. 313-318):
Applying Mendel’s Principles
Genetics Vocabulary
- Genotype
- An organism’s genetic makeup
- Phenotype
- An organism’s physical traits
- Homozygous
- An organism has two of the
same allele for a trait
- Heterozygous
- An organism has two different
alleles for a trait
Probability and Genetics
- Probability is the likelihood an
event will occur
- Can be predicted in genetics
through segregation
- Assumes that each gamete has a
½ chance of carrying an allele
Punnett Squares
- Are named for their creator,
Reginald Punnett
- Are a simple matrix to calculate
the probability of inheritance
outcomes
- Show the possible genotypes
and phenotypes of offspring
Sickle Cell Anemia
Homozygous Dominant Alleles (SS)
Normal red blood cells
Homozygous Recessive Alleles (ss)
Sickled red blood cells
The Principle of Independent Assortment
- Genes for different traits can
segregate independently during
formation of gametes
- Traits that segregate
independently do not influence
each other’s inheritance
- The gene that determines seed
shape does not affect gene for
seed color
Two-Factor Crosses
- Show how the alleles for one
trait are inherited
independently of another trait
- Two dominant alleles don’t
always stay together
- Trick is to show the correct
combinations of alleles in the
parents