BIOL 152 1st Edition Lecture 1 Outline of Current Lecture I. Review of BIOL 151 materialsa. Punnett SquareII. Asexual v sexual reproductiona. Causes of variationIII. MutationIV. RecombinationCurrent LectureI. Review of BIOL 151 materialsAn allele is an alternate form of a gene, whereas a locus is the position on the chromosome where the allele is located. A hydrogen bond connects two helices of a DNA strand, whereas the phosphodiester bond connects the three prime carbon end of one sugar to the five prime end of another sugar. During transcription, RNA polymerase reads a DNA sequence and forms a complimentary, antiparallel strand of RNA. During translation, Ribosomes translate mRNA and form a polypeptide chain resulting in proteins, which carry out important roles in the cell.A punnett square is used to predict the outcome of a cross between two genes. Example: a monohybrid cross for height of a plant, T=tall, t= short T tTtGenotype: 2Tt: 1TT: 1tPhenotype: 3 Tall: 1 shortThese 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. TT TtTt tII. Asexual v. Sexual ReproductionAsexual, 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.III. Mutation 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. IV. Recombination Recombination, or crossing over occurs during the process of meiosis when two homologous chromosomes exchange fragments of DNA. This causes variation and allows for different combinations of DNA to be
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