A101.02GenVar_1 (1)

A101.02GenVar_1 (1) - ANTHROPOLOGY 101: Introduction to...

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ANTHROPOLOGY 101: Introduction to Anthropology Unit 2 Human Variation 0. A central concern of biological anthropology is understanding the nature of the observable variation in human beings 1. This variation occurs at both the individual and group level 2. 3. Sexual reproduction amplifies diversity by increasing the numbers of genetically distinct individuals 0. Each human is potentially capable of producing about 8,388,608 genetically distinct gametes (sex cells) 1. Each pair of parents up to about 70 trillion genetically distinct offspring Key Terms 0. Gene 0. A DNA sequence which codes for a particular protein which produces a particular physical trait 1. Allele 1. One of several versions of the same gene 2. Genotype 2. Your actual complete genetic inheritance 3. Phenotype 3. Your expressed genetic inheritance Genotype 4. Homozygous: 4. Receive two identical alleles for locus 5. Heterozygous: 5. Receive two different alleles for locus Phenotype 6. The expressed form of the gene 7. The observable expression of an individual’s genetic make-up Phenotype vs. Genotype 8. Dominance:
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6. Only one allele of heterozygous pair is expressed 9. Co-Dominance: 7. Both alleles of heterozygous pair are expressed 10. Partial Dominance: 8. The expressed trait is intermediate between alleles of heterozygous pair Genetic Dominance 0. Blood-type A is dominant over O 0. A+A expresses A 1. O+O expresses O 2. A+O expresses A 1. In simple dominance, only one variant is expressed Genetic Dominance 4. The unexpressed variant (allele) is said to be recessive 3. Blood-type O is recessive 2. Recessive alleles only express if an individual receives 2 copies of the same allele Genetic Co-Dominance 3. 4. A+A expresses A 5. B+B expresses B 6. A+B expresses AB 4. In co-dominance, both variants are expressed Genetic Partial Dominance 5. 2. Red+Red expresses Red 3. White+White expresses White 4. Red+White expresses Pink 6. In partial dominance, the expressed trait is intermediate between the variants Polygenetic 7. Most visible & many invisible traits are determined by the interactions of several independently varying genes ( polygenetic ) 8. EX: eye/skin/hair color, schizophrenia, bipolar disorder Environmental Interaction 9. Actual genetic expression is partly influenced by environmental factors 10. Some genetic traits require environmental “triggers” to express 5. EX: Type II Diabetes, bipolar disorder, schizophrenia 11. Other genetic traits can be modified by environmental factors 6. Sources of Population Change 11. Mutation 9. Random change in genetic sequence 12. Selection 10. Non-random changes in gene frequencies reflecting operation of environmental constraints 13. Drift
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11. Random shifts in gene frequency reflecting demographic accidents
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A101.02GenVar_1 (1) - ANTHROPOLOGY 101: Introduction to...

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