ANTHRBIO 201 1st Edition Lecture 5Understanding Variation from molecules to populationsThere are over 7 billion people on earth today-over 1 bil live on less than $1.25/day-richest 1% control 48% of world’s wealth-80st wealthy ppl control 1.9 trillion dollars; same amount shared by 3.5 billionI. Genes are the hereditary materialA. genes occur at specific sites on chromosomesB. each site where we find genes on chromosomes is locus (plural=loci)C. each locus may consist of differentII. DNA is the genetic materialA. DNA molecule is the particle of heredity postulated by Mendel to be responsiblefor the transmission of inherited traitsB. structured as a double helix1. rungs are composed of chemical bases2. C, G, A, T (A/t, C/G)C. 2 important properties1. Stability- faithfully preserves the genetic message2. Replicability- ensures inheritanceIII. DNA ReplicationA. 2 strands unravel, daughter strands bind with new ones that are exact replicasof parent moleculeThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IV. DNA FunctionA. codes for proteinB. constituent of all biological structuresC. proteins made up of strings of amino acidsV. DNA translationA. each of 20 amino acids is determined by a sequence of 3 of the 4 bases1. CGG, CGT, CGA, CGC=alanine2. AAA, AAG= lysine3. codons=3 letter DNA base sequences that code for amino acids4. w 3 letter sequences there are 64 codons, 61 specify amino acids, 3codons simply start and stopB. 2 kinds1. coding sequences specify the structure of proteins2. regulatory sequences determine the conditions under which codingsequences are expressedVI. Molecular genetics summaryA. genes are short segments of DNAB. DNA is translated into protein whose structure is determined by DNAsequencesC. variations in genes and proteins are ultimately responsible for phenotypicdifferencesUnderstanding variation:I. Evolution- change in gene frequencies through timeII. Genes in populationsA. what factors cause gene frequencies to change over timeB. Do ordinary events associated with the life cycle lead to changes in genefrequencies, does mendelian segregation and sexual reproduction lead toevolution?: NO1. sex cell formation and meiosis2. fertilizationC. Assumptions1. population of interbreeding individuals that follow laws of Mendelianinheritance2. Random mating between individualsD. each organism have 2 alleles, A & a1. let p=frequency of allele A, q=frequency of allele a; p+q=1a) q=1-p2. does number of A and a change after sex?a) if p is the probability or frequency of A-bearing gametes, then theprobability of bringing two A gametes together is pxp=p^23. a punnett square shows the frequencies of all possible combinationsa) summing the entries of the table yields(1) p^2AA+2pqAa+Q^2aa=1(2) ^^HArdy-Weinberg equation- shows the genotypefrequencies in the next generation after segregation4. from the hardy-weinberg equation it is easy to show that genefrequencies remain constant under the assumptions of segregation,sexual recombination and random matchingE. Stability of gene frequencies1. frequency of A in the next generation is the fraction contributed by p orp^2 + pq / p^2 +2pq+q^2; left with just p^2+pqF. Lesson1. an important characteristic of Mendelian populations is that irrespectiveof the starting gene frequencies, they will conform to theHardy-Weinberg equation in future generations with the result that genefrequencies will remain unaltereda) other factors must be operating in the real