Mrs. Baxter and Mrs. Herndon 5th Life Science Bill Nye Genetics Video Genetics

1. Genetics is the study of genes, heredity, and genetic variation in living organisms. of a four leaf clovergenetics of a four leaf clover

2. DNA (Deoxyribonucleic Acid) - carries the genetic information for a cell and is a set of instructions that tells the cell what to do or be. 3. Chromosome – a single long molecule of DNA (x shape). pop DNA/brain pop DNA

4. Gene – a part of the chromosome that contains DNA

Traits: What are traits? 1.Traits are characteristics we inherit from your parents. 2.The environment we grow up and live in also helps define our traits. For example: exposure to chemicals or sunlight can change hair color

Genetic traits

5. Inherited trait – a characteristic passed from parents to their offspring. 6. Dominate trait – a strong trait that appears even if the organisms has only one factor. 7. Recessive trait – a trait that appears only if an organism has two factors. 8. Hidden trait – a trait that an organism carries, but is not expressed.

Dominant vs. Recessive Traits ●9. Allele - one of a pair of genes that control a trait, such as blood type or colorblindness. ●Alleles are different “flavors of genes” ●They will be either dominant or recessive traits ●There will always be 1 allele from the Mother and 1 allele from the Father ●a diagram called the Punnett Square ●Punnett Square VideoPunnett Square Video More say of the outcome of that trait No say unless there are 2 recessive alleles

What is Heredity? 10. Heredity - the passing on of traits from parents to a child  We inherit traits from our parents 1.What traits have your inherited from your parents? 2.Why do brothers and sisters resemble each other?

DNA (“De-oxy-ribo-nucleic” Acid) Chemical code  Master copy of instructions for cell structure and function  Give us our traits like hair color, eye color, height, personality, & talents  Each gene makes proteins (building blocks for everything in your body)

DNA (“De-oxy-ribo-nucleic” Acid) Structure (what it looks like)  Three dimensional helix  Spiral staircase or twisted ladder  Humans have 46 pairs of chromosomes (or 23 pairs) Half from one parent & half from another parent

DNA Structure  Cross pieces, “rungs” are made of nitrogen base pairs  Same two bases always pair together: adenine (A) & thymine (T) cytosine (C) & guanine (G)  The matching of the base pairs, (A with T) and (C with G), provides a way for exact copies of DNA to be made called DNA replication.

DNA Mutation  Damaged chromosomes  Mismatched base pairs

DNA Mutation  Mistakes in the DNA  Example: albinism

DNA Discovery/History ( ’s)  Rosalind Franklin 1 st to x-ray DNA DNA X-ray Rosalind Franklin

DNA Discovery/History ( ’s)  Maurice Wilkins gives Rosalind Franklin’s x-rays to James Watson and Francis Crick  Crick and Watson make the 1 st model of DNA  Rosalind Franklin dies of cancer  Wilkins, Watson, and Crick share a Nobel Prize for the DNA model DNA Model

DNA Discovery/History ( ’s) Maurice Wilkins James Watson and Francis Crick DNA Model Sketch