Aim: How do your genetics play a role in the person you are today?  Do Now: What similarities do you have with your parents or siblings?  Homework:Textbook #1-5

Human Genetics

What is Heredity?  The transfer of characteristics from one generation to the next

What are Traits?  A characteristic that is determined by your genes  A pair of genes will determine the trait  Examples:  Tongue rolling  Earlobes  Widow’s Peak  Hair Whorl  Dimples

What is genetics?  The science of how traits are inherited

How are traits determined?  Dominant Genes – the traits that will usually appear in the individual (represented by an uppercase letter)  If an organism has a gene for blue or brown eyes, usually it will have brown eyes because it is the dominant gene  Recessive Genes – The gene hidden by the dominant gene (represented by a lowercase letter)  Blue-eyed people need two recessive genes to show the blue-eyed trait

Who is Gregor Mendel?  “Father of Genetics”  Studied pea plants  He crossed pea plants with different characteristics and studied their offspring  He was able to determine how traits get passed on from generation to generation

What is a Punnett Square?  A table that shows the possible results when the genes of two parents are crossed  It shows the probability of a trait to be expressed in the offspring BB BBBBB bBbBb B – Brown Eyes b – Blue Eyes

What is a genotype?  The genetic code or make up of the individual  Examples: BB, Bb, bb

What is a genotype?  Homozygous dominant – a pair of dominant genes (BB) – a pair of dominant genes (BB)  Homozygous recessive – a pair of recessive genes (bb)  Heterozygous or hybrid – a mixed pair of one dominant gene and one recessive gene (Bb)

What is a phenotype?  The way an organism looks or behaves  Examples: GenotypePhenotype BB Brown Hair Bb

Lets try some Punnett Squares! Examples: Examples:  BB x bb  Bb x bb  Bb x Bb  bb x bb  BB x BB  BB x Bb B = Brown Eyes b = Blue Eyes What we are looking for: 1.Genotypes 2.Phenotypes 3.Percentage Brown eyes 4.Percentage Blue Eyes

Pedigree Charts Allow us to trace certain traits. Helpful for tracking genetic disorders passed down through generations. Ex: Colorblindness

DNA Structure A double helix made of a sugar- phosphate backbone bound in the middle by nucleotide base pairs -The backbone is made up of molecules that have phosphates and sugars – basically the sides of the ladder -The nucleotides, which come in pairs, make up each step of the ladder

Nucleotides Everything that determines what we look like, our likes, our dislikes, whether we’re a morning person or we like to sleep in is largely determined by four nucleotides that are repeated over and over again inside each and of one of our cells. Adenine Cytosine Guanine Thymine These four molecules hold our DNA together by binding together in pairs. Adenine and Thymine will always be paired. Cytosine and Guanine will always be paired. **Guanine will not pair with Adenine, nor Thymine with Cytosine!!!!

Protein Building So how does our DNA actually determine why we are made this way? Earlier in the year, we learned about ribosomes – who synthesize proteins. They get their orders from the DNA.

How?? The ribosomes will read sections of DNA, and every time it reads three nucleotides, it goes and gets an amino acid. Once it has a few amino acids lined up, it chains them together, forming a protein. That protein then goes out to do it’s job, building your body from the ground up! Remember – proteins come in many different forms, think of them like tools – many shapes and sizes, all with very different jobs.

Protein Building

Replication When DNA is copied, it is “unzipped”, separating the two strands of DNA. Once separated, ribosomes work to create a complementary strand. As the complementary strand is formed, the DNA and the new strand are “zipped” together, creating two separate strands of the same DNA. Sometimes, errors occurs. These errors are called mutations

Mutation Mutations can happen for a variety of reasons. Some are good, some are bad. Our DNA has methods built in to find and correct mutations, but not all of them are corrected in time. If mutations are good, helping the organism to survive, there is a chance that they will be passed on to the offspring. This is a gradual change, that ultimately results in evolution over several generations of a species.

Restriction Enzymes  Enzymes that cut DNA at specific locations.

Genetically Engineered Bacteria

 Plasmid (loop of DNA) is removed from bacterial cell  A specific gene is removed from an animal cell  Animal gene is spliced into plasmid  Recombinant DNA is inserted into bacterial cell  Bacteria and it’s descendants will now produce an animal protein

DNA Fingerprinting