1. GENETICS AND HEREDITY
Genes found on chromosomes in the nucleus of a cell, code for the inherited characteristics we call traits
The passing of traits from parents to offspring is known as heredity
The scientific study of heredity is called genetics
Lacking today’s technology the first studies of genetics were based on physical appearance and mathematics

2. GREGOR MENDEL
Mendel was an Austrian monk who loved gardening and mathematics
He designed simple experiments with pea plants to determine how heritable traits were transferred from one generation to the next

3. MENDEL’S PEA TRAITS

4. MENDEL’S CONCLUSIONS
Each trait is controlled by two genes that they receive from their parents
Some genes are dominant over others (shown in capital letters)
Genes that are masked by dominant genes are called recessive genes (shown in lower case letters)
The combination of these two genes determines the traits offspring will exhibit
How often these traits will appear is predictable

5. TERMINOLOGY GENOTYPE  - PHENOTYPE  - PUREBRED (homozygous)  -
HYBRID (heterozygous)  -

6. REGINALD PUNNETT Dominant genes are - Recessive genes are -
Based on the work of Mendel, he developed the “Punnett Square” as a method of predicting the results of a genetic cross (breeding)
Dominant genes are -
Recessive genes are -

7. CROSS #1 t t T - - T - - PHENOTYPE BOX Tall purebred pea plant (TT) x
Short purebred pea plant (tt)
Tall (T)  dominant
Short (t)  recessive
GENOTYPE BOX t t T - -
RESULT: - T - -

8. Tall hybrid pea plant (Tt) x Tall (T)  dominant Short (t)  recessive
CROSS #2
PHENOTYPE BOX
Tall hybrid pea plant (Tt) x
Tall (T)  dominant
Short (t)  recessive
GENOTYPE BOX T t
RESULT: - T - - t - -

9. Principles of Genetics-