BIO 325 1st EditionExam # 1 Study Guide Lectures: 1 - 7Lecture 1 (January 20)Introduction to Genetics: How are traits inherited? How is information stored?What is the central dogma of biological information flow?Traits are inherited through the different forms of genes, called alleles, which are found on the chromosomes. This information is encoded in DNA strands. Size of DNA content and number of genes do not contribute to developmental complexity of a certain species; called the C-value paradox and G-value paradox respectively. The central dogma is that DNA is transferred first intoRNA then into proteins that carry out the necessary functions of the body. The exome is the portion of the genome that encodes exon. What is a genotype/phenotype? A genotype is the DNA sequences present in an individual. A phenotype is how something looks. How is gene function determined? Mutagenesis is the breaking of genes to observe effects; determining genes’ functions. Lecture 2 (January 22)Mendelian Genetics: What were the prevailing theories of genetics before Mendel, and how did he disprove them? The two prevailing theories were the homunculus and blended inheritance. The homunculus theory was disproved by Mendel’s reciprocal crosses and the blending theory was disproved by the fact that traits reappeared in the F2 generation, after being ‘lost’ in the F1.What is Mendel’s law of segregation? Mendel’s law of segregation states that for each trait, there are two copies, called alleles, of a unit of inheritance (genes). During reproduction, the units separate and the egg or sperm (gamete) only contains one of these units.What is Mendel’s law of independent assortment? During gamete formation, different pairs of alleles segregate independently of each other Why was Mendel successful? Mendel chose a great model system that was easy to cross-fertilizeand had a large number of offspring, he chose 7 great traits that were clear cut alternate forms and discrete, he began with pure-breeding lines so that the genotypes were already known, andhe carefully controlled the matings- he performed reciprocal crosses and kept very close track ofwho the parents were for each generation.What is the product rule and when is it used? When we want to find the probability of 2 independent events occurring simultaneously. We determine the product of each of those probabilities What is the sum rule and when is it used? When we want to find the probability of either one oftwo mutually exclusive outcomes occurring. We determine the sum of their individual probabilities. What is the difference between a monohybrid and a dihybrid cross and the phenotypic ratios of each? A monohybrid cross is between 2 plants that differ by a single trait; 3:1 phenotypic ratio, while a dihybrid cross is between two traits; 9:3:3:1 phenotypic ratio. Lecture 3 (January 27)What is the deal with gene behavior in the real world? Not always clearly dominant/recessive More than two kinds of alleles can be present for one geneOne gene can control more than one traitHow do we trace inheritance in humans? By the use of pedigreesa. Pedigree for a recessive diseasei. Occurs rarely unless consanguineousii. Assume all other individuals are homozygous normal unless there is evidence to say clearly otherwiseiii. All of the children of 2 affected parents should be affectediv. Rare recessive traits show a horizontal pattern of inheritance1. Can be vertical if the trait is extremely common in the populationb. Pedigree for a dominant allelei. Diseased individual is assumed to be heterozygous unless every child has the diseaseii. Affected children always have at least one affected parentiii. Show a vertical pattern of inheritanceWhat is the difference between incomplete dominance and codominance, and do Mendel’s laws still hold in both? In incomplete dominance, neither allele is dominant or recessive, but instead, both contribute equally to the phenotype of the F1. Each genotype has its own phenotype. In codominance, both of the parental phenotypes are seen in the F1 hybrid. Mendel’s laws still in fact hold in these cases because the activity of the alleles is still the same.Pleiotropy- One gene may control multiple phenotypes; multiple phenotypes will segregate togetherLecture 4 (January 29)What are the genetic complexities that deviate from Mendelian Genetics, and what are the processes of each? Complementary gene action is when genes have effects in pairs, resulting in a 9:7 phenotypic ratio. Epistasis can be either dominant or recessive, and occurs when alleles of one gene mask the effect of alleles of another geneHow can the environment affect the phenotype? Temperature-sensitive alleles are when gene products only function in a limited temperature range, and temperature-dependent sex determination can be seen in crocodilesWhat is the difference between penetrance and expressivity? Penetrance is the frequency at which individuals with a given genotype show the associated phenotype, while expressivity is the degree to which the phenotype is exhibited. In penetrance you want to ask, “is the phenotype being expressed?”, in expressivity you want to ask, “to what extent?”Binomial Probability Formula: P (k number of event n) = [n!/k!(n-k)!] x p^kq^(n-kLecture 5 (February 3)What is the sum of all probabilities, and how can that information be used to answer an “at least” question? The sum of all probabilities is 1. When answering an “at least” question, use the sum of all probabilities, and the probability of all other exclusive events using the formula: 1-p(all other exclusive events). Mitosis- produces the exact same number of cellsi. Number of chromosomes does not chain after S phase; amount of DNA just doubled.ii. Results in 2 diploid daughter cells; genetically identicalMeiosis: produces haploid cells; ½ as many chromosomes as parentsiii. Results in 4 haploid daughter cells; genetically uniqueiv. Crossing Over, also referred to as Homologous Recombination- produces recombined gametes; Homologous chromosomes exchange genetic informationAnatomy of a chromosomeCentromere- the center point where the sister chromatics are joinedSister chromatids- Exact copies of each other (x)Nonsister chromatids- Chromatids of different chromosomesNonhomologous chromosomes- Non related pairs of sister chromatids; carry completely unrelated sets of genesHomologous chromosomes- The pair of sister chromatids (xx); Contain the same set of