BIOL 152 1st Edition Exam 1 Study Guide Lectures 1 8 Lecture 1 January 13 What is a punnett square and what is it used for A punnett square is a method that is used to predict the outcome of a cross between two genes A punnett square predicts possible genotypes of a monohybrid cross What is the difference between asexual and sexual reproduction Asexual or clonal reproduction occurs when one parent cell creates an identical daughter cell with an identical nucleus Sexual Reproduction occurs when two parents pass on their genes to their offspring each parent only contributing half of the genes In both asexual and sexual reproduction there is a chance of variation from parent to offspring because of mutations and recombination What are the different types of mutations that can take place during replication There are several types of mutations that can take place during the process of replicating the parents DNA Mutations are changes in the DNA and occur whether or not they benefit an individual Point mutations occur on set of nucleotide base pair and do not affect the protein being made The types of point mutations are silent mutations missense mutations and nonsense mutations Silent mutations have no affect on the amino acid being created A missense mutation results in a different amino acid and nonsense mutation results in the formation of a stop codon which results in a non functioning protein Another type of mutations are insertions and deletions and occur when a base pair is added or removed these types of mutations cause a frame shift which can be harmful to the protein being formed Lecture 2 January 15 What are the causes and consequences of mutations Mutations can be caused by DNA replication errors known as spontaneous mutations or mutations could be the result of environmental influences such as radiation or chemicals The consequences of mutations can be harmful neutral or beneficial Studies have shown that mutations occur randomly and are not usually caused by environmental influences What is evolution and how does natural selection relate to evolution Evolution is the scientific theory that explains how Earth s species have changed over time which accounts for diversity in form and function Charles Darwin put this theory forth after his trip to the Galapagos Islands Charles Darwin also coined the term Natural selection to account for the variations within a species Natural selection is the mechanism of evolution This term refers to individuals who are best adapted to survive Nature selects which genes are to be passed to the next generation and which are to be eliminated Survival does not necessarily mean that an individual s genes will be passed on to the next generation fitness is also an important factor Fitness refers to an individual s contribution to the gene pool Differential reproduction or the unequal chance of individuals to survive and reproduce leads to the accumulation of advantageous traits over time Lecture 3 January 20 How is evolution applied to a population A population is localized group of individuals in a species that are capable of interbreeding A genome is the total genetic complement of individual organisms the two types of genomes are nuclear genomes and mitochondrial genomes The gene pool is all the allele at all gene loci in all individuals of a population Evolution in regards to population refers to the changes in frequencies of genotypes or alleles Natural selection changes the gene pool of a population because some genes are eliminated and not expressed Natural selection affects an individual but the population evolves What does the Hardy Weinberg Principle explain This principle states that frequencies of alleles and genotype in a population s gene pool remain constant from generation to generation Hardy Weinberg Equilibrium is maintained by the following conditions no natural selection no gene flow no mutations large population size and mating is random Lecture 4 January 22 What is the Hardy Weinberg equation and what is it used to find Hardy Weinberg Equation is p2 2pq q2 and it is used to find the Genotype and allele frequency Where P2 expected frequency of one of the homozygous genotypes2PQ expected frequency of the heterozygous genotypeQ2 expected frequency of the other homozygous genotype What are the conditions of evolution Mutations nonrandom mating natural selection gene flow and small population size are all conditions for evolution Mutations alter the allele generate a new allele or duplicate an allele Nonrandom mating changes genotype frequency because of interbreeding and an individual chooses a mate because of a specific phenotype i e height or size Natural selection is a consistent means of adaptive evolution the selection increases the frequencies of certain alleles those that increase fitness Gene flow refers to the transfer of genes between populations through interbreeding This changes the allele frequency and reduces differences overtime Lecture 5 January 27 What are the different types of selection Positive selection increases the frequency of certain alleles resulting in adaptation and increased fitness this selection can promote fixation of certain alleles On the other hand negative selection decreases frequencies of harmful alleles that reduce fitness Balancing selection is the maintenance of two or more alleles in a population This selection provides a heterozygote advantage or better resistance to an ailment Natural selection can alter the frequencies of heritable traits through three main types of selection stabilizing selection disrupting selection and directional selection Stabilizing selection acts against extreme phenotypes and favors intermediate forms of the phenotype Disrupting selection favors the two extremes of a phenotype when the environment is disrupted Directional Selection is similar to disruptive but favors only one extreme of a particular phenotype Artificial Selection occurs when humans select individuals with desired traits and uses them as breeding stock Some examples of artificial selection are domesticated dogs and domesticated plants Sexual selection occurs to enhance the individual s ability to reproduce successfully How is genetic variation preserved There are several factors that ensure that there is genetic variation within a population such factors are diploidy and balancing selection Diploidy occurs when genetic variation is hidden as a recessive gene This means that an individual