Week 1 Notes
Week 1 Notes
Popular in Course
Popular in Department
verified elite notetaker
This 10 page Class Notes was uploaded by Alix Bikker on Friday January 16, 2015. The Class Notes belongs to a course at a university taught by a professor in Fall. Since its upload, it has received 333 views.
Reviews for Week 1 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 01/16/15
BIOL 241 Genetics Lecture 2 11415 Homologous chromosomes DO NOT PAIR IN MITOSIS During meiosis the pairing of the homologous chromosomes at the equatorial plane is seen in the metaphase of meiosis I Theories of heredity before Mendel Preformationism there is a preformed miniperson homunculus inside an egg or a sperm 0 Problems only one parent contributes to the offspring a homunculus within a homunculus Pangenesis quotparticlesquot carrying info from various parts to the reproductive organ 0 Inheritance of acquired characteristics 0 Lamarckism use and disuse Blended Inheritance parental traits are mixed and become forever changed in the offspring o This is problematic for the theory of evolution because desirable traits will be diluted in subsequent generations if inherited traits are blended Mendel used the garden pea as his model and it was a good model organism because 0 Ease of cultivation Rapid reproduction Small size Fecund Mutants are available and easy to identify 0 Broad literature and experimental background available He cut the ends of the anthers of the purple ower transferred the pollen with the brush and put it on the white ower and then all baby owers were purple Monohybrid Cross mating between individuals that differ in only one trait 0 Ex homozygous round seed homozygous wrinkled seed Reciprocal cross Mendel39s monohybrid crosses were not sex dependent the results were the same 0 Dealing with autosomal inheritance Autosomal versus sex chromosome linked how to tell difference 0 Perform reciprocal crosses Dominant vs Recessive o Traits blending did not occur 0 The wrinkled seed shape must have been present but unexpressed in F1 0 Dominantround recessive wrinkled Nomenclature 0 Dominant unit factors are designated with a capital letter amp often the rst letter of the description recessive are represented by small letters EX roundR wrinkledr OOOO BIOL 241 Genetics F2 ratio was usually 31 when Mendel was doing experiments Mendel39s explanation 0 Existence of genes responsible for contrasting phenotypic differences 0 Genes in pairs Different forms of genes are called ALLELES o Halving genes pairs in gametes 31 both parents are heterozygous for one gene Genotype vs Phenotype o The genotype is the genetic makeup of an individual 0 The phenotype is the physical expression of the genetic makeup 0 31 is a phenotypic ratio and 121 is a genotypic ratio Homozygous vs Heterozygous 0 When alleles for a trait in an individual are the same the individual is homozygous o Alleles differentheterozygous Test cross 0 Way to determine whether an individual displaying the dominant phenotype is homo or heterozygous for that trait o Phenotype of the progeny genotype x homozygous recessive Progeny phendtypic ratio GenotyWestion Mendel39s second aw gene pairs on different chromosome pairs assort independently at meiosis The product rule the probability of independent events occurring together is the product of the probabilities of the individual events BIOL 241 Genetics 0 From the monohybrid you know that from round wrinkled is 31 and yellow green is 31 So dihybrid ratios arequot 0 Round Yellow 34 x 34 916 0 Round 6134 X 14 Wrinkled Y 14 x 34 0 WG 14 X 14 0 Sum Rule the probability of either the tow mutually exclusive events occurring is the sum of their individual probabilities O YY14andyy14 Dl41412 Dihybrid ratio of 9331 two genes on different chromosomes they are uanked 0 Both parents are heterozygous at both genes
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'