1. Genetics Notes
3/2/18

2. Genetics The study of heredity
Heredity: The passing on of a physical or mental characteristic genetically from one generation to the next.

3. How does heredity/genetics work?
Offspring (children) may have similar physical characteristics (traits) as their parents because genetic information (DNA) is passed from the parent to the offspring.
Each sex cell contains ½ of the genetic material needed to create a new organism.
When the cells are joined the genetic material combines to create the traits of the offspring.

4. Chromosomes
A structure found in the nucleus of a cell that contains genetic material (DNA)
Each Chromosome is composed of long strands of DNA

5. DNA Deoxyribonucleic Acid  YOU HAVE TO KNOW THIS
Forms a double helix structure.
Composed of 4 nitrogenous base pairs
A- Adenine
T- Thymine
C- Cytosine
G- Guanine
The back bone or sides of the structure are a phosphorous and sugar composition

6. DNA Structure Adenine ALWAYS pairs with Thymine (A-T)
Cytosine ALWAYS pairs with Guanine (C-G)
Nucleotide: Building blocks of DNA (A, T, G, C)
Codon: A combination of 3 nucleotides (ATT GCA CAT GAT GAC)
The combination of codons forms your DNA.

7. Gene Carries the information that determines an organisms trait.
Responsible for the inherited characteristics that distinguish on individual from another.
Generally come in pairs one gene from one pair is called an allele
Genes can be considered in 2 ways:
Genotype: The set of genes carried by the organism
The genetic make up (Allele)
Phenotype: The physical expression of the gene
What we see on the outside

8. Allele One gene that forms a pair. 2 types of Alleles
Dominant: A trait that will always show up when the allele is present
Recessive: A trait that only appears if both alleles in the gene are recessive.

9. Gregor Mendel
Austrian Monk responsible for observing the first stages of heredity and genetics.
Around 1854 Mendel began to observe a garden full of pea plants.
He noticed that several characteristics were different from plant to, but they were similar to the traits the parent plant had.
He did extensive work in cross breading a variety of pea plants that led to the explanation of how traits are passed from one generation to the next.
He used tens of thousands of plants to help explain what he was observing.
His discoveries and observations are the foundation of todays study of genetics