Genetics Bill Nye Genetics Video Genetics

1. Genetics  The study of the way physical traits and characteristics get passed down from one generation to the next.

2. Gene – a part of the chromosome that contains the DNA code for an inherited trait EACH CELL in your body has 25,000-30,000 genes! The nucleus contains chromosomes and genes. (46 individual chromosomes/23 pairs) FUN FACT: Fruit fly – has only 4 chromosomes!

3. Inherited trait – a characteristic passed from parents to their offspring. 4. Dominate trait – a strong trait that appears even if the organisms has only one factor. 5. Recessive trait – a trait that appears only if an organism has two factors for the trait 6. Hidden trait – a trait that an organism carries, but is not expressed or shown

7. Gregor Mendel  19 th century Austrian monk  Early experiments with pea plants  How traits are passed from parents to their offspring

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

8. Punnett Square  is a diagram that is used to predict an outcome  It is named after Reginald C.Punnett.  used by biologists to determine the probability of an offspring having a particular genotype.

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 Video Punnett Square Video More say of the outcome of that trait No say unless there are 2 recessive alleles

Genetic traits

How do Genes work? Genes have the special job for making proteins in the cell. Each gene in the body may make as many as 10 different proteins! Genes come in pairs Each of your parents has two copies for each other their genes, and each parent passes along just one copy to make up the genes you have.

10. 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. 11. Chromosome – a single long molecule of DNA (x shape). pop DNA/brain pop DNA

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.

What is Heredity? 12. 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? Heredity VideoHeredity Video BrainPop StudyJams videoStudyJams video

. of a four leaf clovergenetics of a four leaf clover

 Damaged chromosomes  Mismatched base pairs

DNA Discovery/History ( ’s)  13. Rosalind Franklin: was an English chemist and X- ray crystallographer who made contributions to the understanding of the molecular  structures  of DNA DNA X-ray

DNA Discovery/History ( ’s)  Maurice Wilkins gives Rosalind Franklin’s x-rays to James Watson and Francis Crick  14. Francis Crick and James D. Watson – molecular biologists who discovered the structure of DNA and made 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