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Unformatted text preview: 9-2-10 Genetics I. Terms a. Genotype: structure of your genes b. Phenotype: way in which genotype is expressed - Genotype sets boundaries for phenotype (not proven true). - Experiences (environment) determines where within boundaries the phenotype will lie. c. Gametes: reproductive cells (sperm and eggs) d. Somatic cells all body cells besides gametes e. Genes and DNA - Genes contain info for making specific proteins. Specific proteins are translated into specific characteristics. - Genes comprised of DNA molecules. - DNA molecules arranged in a spiral staircase (double helix) - Each step contains 2 chemical base pairs: A (Adenine) and T (Thymine) G (Guanine) and C (Cytosine) - A gene may have 1,000 steps (about 20,000 to 25,000 genes) - Ordering of steps in a gene determines which proteins are made - Alleles different forms of the same gene For each gene, you inherit one copy from Mom and one from dad (Exception genes on sex chromosomes in males) Ex1. Blood type: A, B, O - Homozygous both copies of a gene have the same allele - Heterozygous both copies of a gene have different allele f. Chromosome - String of genes - Humans have 23 pairs of chromosomes (46) 1 pair sex chromosomes, F=XX, M=XY 22 pairs are autosomes, same for M and F. Members of the same pair are homologous (i.e., refer to same traits in same order) ...
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- Fall '08