1. Agenda 07/16/2010 How do we get our enzymes? Genetic Molecules Enzyme Synthesis Review

2. THINK…. So, if comes from biological parents… But…How many chromosomes in each cell? – 46 +46 = 92 – 23 + 23 = 46  how get…

3. Meiosis and Fertilizatio n So, again, are all individuals in a population identical? Diversity/Variation or go extinct (p.310-311) – “herd” of DNA = Natural Selection – Survive Reproduce  offspring mix of successful genes (p.312- 313) Chance get trait – 50/50??? NO!- Dominant vs. Recessive, Incomplete, Codominate, X-linked Lifeworks glossary, p.310-315 Define Meiosis Define Fertilization

4. Meiosis – p. 315 Cell with 46 chromosomes Chromosomes Double, 92 Embrace, or “flip” info, 92 chromosomes transfer or “cross over” info, 92 chromosomes Cells split, so now 46 chromosome in 2 cells Cross over happens again, 46 chromosomes Both cells split, so now 4 cells of 23 chromosomes So from 1 cell of 46 chromosomes  4 different cells of 23! What do we call these cells of 23 chromosomes.. – Sex cells = Gametes (or gamete) – Sperm and Ova (egg)

5. Fertilization – p.314 Remember.. – Biological parents had biological parents – Our Gametes are a mix of our biological parents, who area mix of theirs, who are a mix of theirs…(meiosis)  not identical! Ova and Sperm combining.. – Mix of genetic information – “Recombining” – 23 +23 = 46 – No Master Plan  chance sperm/egg Offspring – Mix of info – Biological Grandparents

6. Review - DNA Structure, p. 152 How is the genome like a set of books? Letter = nucleotide bases Word = 3 bases (gene) Paragraph = string of genes to give protein Book = chromosome Volume of books = genome Genome??? All genetic information for an organism Humans have chromosomes in their genome 1 st chromosome finished in 1999 All by 2003 Still working on the details and