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Genetics by Mind Map: Genetics

1. Human Genome Project

1.1. Complete copy of the entire set of human gene instructions

1.2. 2003

2. Chromosomes

2.1. DNA coiled around proteins

2.2. Human: 46

2.3. 23 pairs

2.3.1. First 22 pairs are called autosomes

2.3.2. 23rd pair called sex-gender

3. Genes

3.1. Code for specific trait

4. DNA

4.1. Structure

4.1.1. Double Helix Discovered by James Watson and Francis Crick - 1953 Nucleotide = Phosphate, base and sugar Base

4.2. Replication

4.2.1. Enzymes (protein) break up the DNA cell and helps form identical DNA cells

4.3. Cell Division

4.3.1. Mitosis - Somatic (body) cells Stages: Interphase: where DNA gets photocopied (starts of as mother cell) Prophase: Centrioles produce spindle fibers (like spaghetti), sister chromatids (2 sets), nuclear membrane dissolves Metaphase: Chromatids line up on metaphase plate (middle), spindle fibers connect to centromere, centrioles go to opposite poles (like north and south pole) Anaphase: Spindle fibers pull chromatids apart and move to the ends of cells Telophase: Nucleus forms (ends as daughter cells), chromosomes decondense Cytokinesis: Division of cytoplasm

4.3.2. Gamete Production: Meiosis (Reproductive cells) Meiosis I Interphase I: Chromosomes duplicate Prophase I: Homologous chromosomes pair and exchange segments/switch and crossover (Synapsis - pairing of homologs to form tetrads/4 pairs of chromosomes) Metaphase: Tetrads line up in the middle Pairs of homologous chromosomes split up (becomes sister chromatids again) Telophase & Cytokinesis: Two haploid (half of the original information) cells form; chromosomes still double Meiosis II Prophase II: Spindle fibers form again Metaphase II: Sister chromatids (23) line up in the middle Anaphase: Sister chromatids separate = 23 chromosomes Telophase II: Haploid daughter cells forming Sister chromatids finally separate; four haploid daughter cells result, containing single chromosomes

4.3.3. Haploid (n): 1 set of chromosomes in gametes

4.3.4. Diploid (2n): 2 sets of chromosomes. One from each parent