1. Genetics and Heredity

2. Gregor Mendel Austrian Monk. Experimented with “pea plants”.
Used pea plants because:
They were available
They reproduced quickly
They showed obvious differences in
the traits
Understood that there was something that carried traits from one generation to the next- “FACTOR”.

3. Law of Dominance
Law of Dominance: When there is a dominant allele, ONLY the dominant trait will be expressed, even if there is a recessive allele in the pair.

4. Alleles Alleles are different versions of a specific gene.
A gene talks about an actual trait, while an alleles is the specific version of that trait.
For example the gene may be hair, but the hair color is the allele.

5. Dominant and Recessive
Dominant- traits that are expressed (shown, present). This is represented using a capital letter.
For example: T= Tall, R= Red, B= Yellow
Recessive- traits that are covered up. This is represented using a lowercase letter.
For example: t= Short, p= white, c= Curly

6. Homozygous and Heterozygous
Homozygous- two of the same alleles. (RR or rr)
RR is said: homozygous dominant
rr is said: homozygous recessive
Heterozygous- two different alleles. ( Rr)
You only have to say heterozygous, and not whether or not it is dominant or recessive.

7. Genotype & Phenotype
Genotype- the types of genes (Alleles) present. Represented as RR, Rr, or rr.
Phenotype- what it looks like. Represented by adjectives. Red, Skinny, tall, curly.

8. Punnett Squares and Probability
Punnett square: diagram showing the probabilities of the possible outcomes of a genetic cross

10. Write the genotype in each box
Write the phenotype in each box.
Tell me the probabilities for the overall box.

11. The Importance of the Environment
The environmental influences the expression of the genotype so the phenotype is altered.
Hydrangea flowers of the same genetic variety range in color from blue-violet to pink, depending on the acidity of the soil.
Multifactorial; many factors, both genetic and environmental, collectively influence phenotype in examples such as skin tanning

12. How is it possible to maintain such genetic continuity?