What type of cells are these?

Discovering - DNA 1800’s – with discovery of microscope, scientists realized something [DNA] existed in the nucleus 1950’s – Rosalind Franklin- using X-ray discovered a stand of DNA consists of a “double helix” or spiral shaped ladder - Watson and Crick- “ sides of ladder” consists of sugars and phosphates and “steps of ladders” are nitrogen base pairs Video: Cracking the Code of Life | Watch NOVA Online | PBS Video

DNA DNA- [Deoxyribonucleic Acid] threads of chromatin phosphate DNA- [Deoxyribonucleic Acid] threads of chromatin Sugar Shape - like a spiral ladder 1. Rungs = Pairs of Nitrogen Bases A-T = Adenine - Thymine G-C = Guanine - Cytosine 2. Handrails = Alternating Phosphate and Deoxyribose Sugar * Base pairs always attached to sugar Nitrogen base

Inside the Nucleus Gene - a section of DNA coil, determines traits of organism Heredity- passing of genes from parent > offspring

Alleles - different forms a gene may have for a trait Genetics- study of how alleles affect generations of offspring

Number of Base Pairs [millions] Chromosome Number of Base Pairs [millions] 1 279 2 251 3 221 4 197 5 198 6 176 7 163 8 148 9 140 10 143 11 12 142 13 118 14 107 15 100 16 104 17 88 18 86 19 72 20 66 21 45 22 48 X / Y 163 / 51 98% of genes for Humans & Chimps are alike Total Base Pairs = 3.2 billion Total Genes = 30,000 Genes between Humans only differ by 0.01% To read all 3.2 billion base pairs aloud -it would take 9.5 years The Human Genome Project, 3D Animation - YouTube

http://www.youtube.com/watch?v=D3fOXt4MrOM Mutations A-T-C-A-T-T-C-T-G

Making Proteins A-T-C-A-T-T-C-T-G

Mutations http://svtube.svsd.net/play/?id=uywatntjuf

Down’s Syndrome http://svtube.svsd.net/play?id=uhpbnqaafk

Seedless Grapes? Grafting/Cuttings http://www.youtube.com/watch?v=RjsU_rJpTWg Grafting/Cuttings http://www.youtube.com/watch?v=a-lL_ikaxtY

Meiosis

Alleles One comes from mom, one from Dad Chromosome Dad Mom Eye color Gene

Genetic Cross- random pairing of one gene from each parent Gregor Mendel = Father of Genetics Dominant- “what is seen” [Capital letter] Recessive- “what is hidden” [Lower case letter] Phenotype- physical trait that appears ex: Tall Genotype- genetic make-up or letters ex: TT Homozygous [homo means same, zygous means pair] = TT, tt Heterozygous [hetero means different, zygous means pair] = Tt

Monogenic Inheritance Dominant Traits Tongue roller Hand clasp Unattached earlobe Straight Pinky Hairy finger- 2nd section Dimples Cleft Chin Straight hair line Freckles Hitch hiker thumb Brown eyes Second toe longer than big toe 13. Finger divide- 2 vs 1 14. PTC

Punnett Squares- visual tool used to display the possibilities of a genetic cross Mom’s Traits D a d’ s T r i t

Punnett Squares

For For the Wisconsin Fast plant, purple stems are dominate to green stems. After growing several hundred plants, Johnny realizes that 75% of the offspring have purple stems and 25% of the offspring have green stems. Find the genotypes of the parents using a Punnett square.

DNA Unit Review What are the steps of the DNA ladder made of? Nitrogen Base Pairs : A-T, G-C 2. What are the sides of the ladder made of? Phosphates and sugars 3. What are base pairs always attached to? Sugar 4. Where are genes located? On chromosomes 5. Different forms of the same genes are called? Alleles

6. Physical appearance of a trait is called? Phenotype 7. Genetic make up of an organism? Genotype 8. What does the term heterozygous mean? Homozygous? Different gene combinations, dominant and recessive Same gene pairs What is a mutation? Are they always harmful? Permanent change to an organism No create variety

10. What is the purpose of using a Punnett square? Determine probability of traits that can be inherited 11. What is the process that involves one cell dividing two times to create four new cells with half the number of chromosomes? Meiosis 12. What type of cells undergo meiosis? Sperm and Egg How many chromosomes are in a human egg cell? 23 ----- Why not 46?

What is it called when many genes create ONE trait? polygenic inheritance What is the term for more than two possibilities of a trait? multiple alleles 16. When both genes are expressed equally for a trait it is called? incomplete dominance

Creation of Proteins Base pairs form amino acids which link together to form proteins