Intro to Genetics Read p 2-6

Intro video https://app.discoveryeducation.com/learn/videos/8e340425-0b8e-4c6d-b088- 18caf08227bb?hasLocalHost=false

Ice land video https://www.cnn.com/videos/health/2017/03/20/vital-signs-iceland-genome- a.cnn

Human genome project https://www.youtube.com/watch?v=AhsIF-cmoQQ

I. Genetics = A. Study of heredity 1. how traits are passed to other organisms 2. How environments affects inherited traits B. Study of the mechanisms of genetic transmission 1. Genes 2. chromosomes C. Study of gene expression

II. Prokaryotic Gene transmission A. linear gene flow – genes passed on by reproduction 1. Prokaryotic fission - BACTERIAL CELL DIVISION - PRODUCES CLONES - NO RECOMBINATION OF GENES SO NOT SEXUAL REPRODUCTION

B. lateral gene flow – genes passed to neighboring cells 1. conjugation – bacteria pass plasmid genes along cytoplasmic bridge (may be different species)

2. Bacterial Transformation – bacteria pick up DNA from environment 3. Transduction - virus transfers gene into bacteria

III. Eukaryotic gene flow only linear A. Asexual – no recombination of genes 1. via mitosis 2. produces clones 3. advantage : rapid, lower energy 4. examples - binary fission in protists - budding - clonal propagation

B. sexual reproduction – genetic recombination 1. non-identical gametes formed via meiosis 2. genes of parents combined by fertilization 3. Advantage : produces genetically different offspring 4. Disadvantage : requires more energy, slower

Iv. Mitosis A. nuclear division to – 1. grow 2. replace worn cells 3. repair tissues 4. do asexual reproduction

B. Animal mitosis – 2n cell divides to make two 2n cells 2N means each cell has 2 of each type of chromosome 2n number for humans = 46 2 of each of 23 different types of chromosome N = chromosome number 2(N) = 2(23) = 46

C. Before mitosis can take place cell must copy DNA 1. DNA replication makes identical copy of each chromosome 2. duplicate chromosomes remain attached by centromere 3. duplicate chromosomes are called sister chromatids

D. phases of mitosis = pmat 1. P = prophase ….chromosomes condense nuclear envelope breakes down spindle forms 2. M = metaphase…..C line up single file at equator 3. A = Anaphase….centromere broken and sister chromatids move away from each other 4. T = sister chromatids reach opposite poles

E. cytokinesis most often follows mitosis 1. cell divides into 2 identical cells 2. called daughter cells

V. Meiosis A. Two nuclear divisions B. Mieosis I – 1. separates homologous pairs of c 2. converts 2n cell into 1n cell (still X shaped C) C. Meiosis II – 1. separates sister chromatids 2. converts X shaped C into single chromosomes

d. What is different about meiosis I Prophase I : same as mitosis + Synapsis & crossing over Metaphase I : C line up in pairs

VI. How/Where Haploid Cells are produced A. Where: Animals: Meiosis only in gonads 1. Gonads = reproductive organs a. testis b. ovary 2. Specialized cells in gonad do meiosis a. spermatocytes b. oocytes 3. Spermatocytes and oocytes are constantly replaced by specialized Spermatogonia cells & oogonia cells

VII. Spermatogenesis A. Spermatogonia cells do Mitosis make 1. a 1◦ spermatocyte 2. a cell that stays a spermatogonia B. The 1◦ spermatocyte does meiosis to make 4 spermatids

VIII. Oogenesis Oogonia do Mitosis to make 1 primary Oocyte Which does… Meiosis I to make 1 secondary oocyte and one polar body Meiosis II makes 1 ovum &1 polar body