Genetics Review

Honors Human Anatomy & Physiology

Mr. Mazza 2009-10

Why review genetics in a course on anatomy & physiology?

Genes control the layout, make-up and function of the bodies of all organisms. Examples of traits influenced by genes:

• Appearance (hair, skin, eyes, height, etc.)

• Body structure of an organism

• Susceptibility to diseases

• Personality traits

• Behavior (instincts as well as other behaviors)

*Environment interacts with genes to produce the final phenotype (physical trait)

50% of your genesfrom dad

50% of your genesfrom mom

Where do your genes come from?

It’s the stuff that genes are made of: DNA

• made of 4 nitrogenous bases (adenine, guanine, cytosine, thymine)

• A pairs with T; C pairs with G

• Each gene is a unique sequence of the 4 bases

CHROMOSOME

DNA

gene

What information do genes contain?

• Each gene on the DNA is an instruction to build a protein

• Proteins are the main structural components of the body (bones, muscle, skin, hair, nails, blood vessels, organs, etc.) and regulate all chemical reactions in the body

Human Karyotype

From Genes to Proteins

How a protein is made

DNA

ribosomes

mRNA (has copyof DNA information)

Translation(making of a protein)

Transcription (making of RNA)

protein

Each protein is made of amino acids - every 3 bases is a codon (code) for one amino acid

The Genetic Code

mutationA change in the genetic code

DNA RNA PROTEIN

MutatedDNA

MutatedRNA

Defectiveprotein

Flow of genetic information in a cell(Central dogma of molecular biology):

Why is this important?

• Our susceptibility to any disease is affected by the variations of genes we inherit from our parents and/or mutations we get via the environment (i.e. radiation, chemical exposure, etc.)