Questions… • 1. Identical twins are always the same gender • 2. Males and females have all of the same chromosomes • 3. A female that is not color blind can have color blind children • 4. A man with brown eyes can father a child with blue eyes • 5. A persons blood type is determined by more than two genes. • 6. Mendel studied and manipulated pea plants in order to understand genetic inheritance, and phenotype • 7. A persons phenotype is as a direct result of their phenotype. • 8. All people carry their mothers mitochondrial (mitochondria) DNA • 9. If a person develops cancer due to overexposure to sunlight their children are likely to be born with cancer causing genes (DNA) • 10.Half of a persons genes come from each of their parents. • 11 A person can only pass on either the genes they received from their Mother, or the genes they received from their Father • 12.All living things have genetic material that they pass to their “offspring” • 13. DNA is made of proteins.
Expectations. • An Introduction to me. • Pre unit quiz, and identify the chapters for the week…
Heredity and Inheritance Genetics unit part … Written by Kate Valentine.
What is DNA? • De-oxy-ribo-nucleic acid • The instruction book for life • Where? • In every cell of our bodies. • How does it tell our bodies what to do? • It has a code that our cells can read • What does this look like? • The instructions are written in a chain of nitrogenous bases that are twisted shape is called a Double Helix • Like a twisted zipper
DNA and its discovery • Rosalind Franklin • X-Ray Crystallography • Didn’t receive any credit for her discovery until after her death. • Watson and Crick • Never did experiments but did a lot of research and used data from others they realized the structure (1953) was a double helix and won a Nobel prize(1962)
Nucleotides DNA is made of repeating subunits called nucleotides. • 3 parts • Simple sugar (deoxyribose) • Phosphate group • Nitrogenous base
Nitrogenous Bases • 4 possible types • Adenine (A) • Guanine (G) • Cytosine (C) • Thymine (T) • A always pairs with T • C always pairs with G The DNA strand is made of letters: ATCCGTAATGAGCCTCGA These letters make “words”: ATC CGT AAT GAG CCT CGA These words make “sentences”. These sentences are called genes. Genes tell the cell to make other molecules called proteins. Proteins enable the cell to perform special functions. (ie: to make hearing possible)
Life and DNA • DNA is the blueprint for life. • It tells our bodies how to build new cells • The blueprint is different for all living things, but made of the same pieces. • The same letters words and sentences are in all of us • The code to build a eye in us is almost identical to the code to build the eye of a dog, or mouse, or even snake, or insect!
What is DNA Used for?? • DNA holds the instructions for making every protein and part of our bodies • DNA is important because Every Cell in the body has to be able to make a replacement for itself before it dies, or more so that we can grow.
What Holds DNA together?Why AT GC? • Weak hydrogen bonds hold together the two strands of DNA • These bonds form between Adenine and Thymine, and Guanine, and Cytosine • Why AT GC?? • Adenine and Thymine form a double bond together • Guanine and cytosine form a triple bond.
Replication. P 286 • During the Interphase stage of cell division (Mitosis) the chromosomes must be replicated so that the two new cells will contain identical DNA • To start this process • Hydrogen bonds (weak) unzipped, one piece at a time free floating nucleotides are added onto each side of the DNA chain until the entire length is replicated. • Complementary strand of DNA is produced.
Replication • Replication fork… DNA polymerase. • cutting a ladder in half • two identical ladders • This strand is then a copy of the DNA. • new cell when the old cell divides, and replicates • What happens if there is a mistake???
Mutations (Sec 11.3) Reproductive Cells Body Cells • Sperm or Egg cell • If this cell takes part in fertilization, all the cells will have the mutation. • Non reproductive cell • ie. Skin, muscle, bone • When cell divides, the new cell will have the same mutation
See YOUR DNA • Biology\Cracking the Code of Life.docx • Biology\Protein Synthesis and Words.docx • Activity!