* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Introduction to Genetics
Human genetic variation wikipedia , lookup
Gene therapy wikipedia , lookup
Pharmacogenomics wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Gene nomenclature wikipedia , lookup
Genetic drift wikipedia , lookup
Public health genomics wikipedia , lookup
Population genetics wikipedia , lookup
Gene desert wikipedia , lookup
Hardy–Weinberg principle wikipedia , lookup
Genetic engineering wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Minimal genome wikipedia , lookup
Ridge (biology) wikipedia , lookup
Site-specific recombinase technology wikipedia , lookup
Nutriepigenomics wikipedia , lookup
X-inactivation wikipedia , lookup
Genome evolution wikipedia , lookup
Biology and consumer behaviour wikipedia , lookup
Gene expression programming wikipedia , lookup
Quantitative trait locus wikipedia , lookup
History of genetic engineering wikipedia , lookup
Epigenetics of human development wikipedia , lookup
Gene expression profiling wikipedia , lookup
Genomic imprinting wikipedia , lookup
Genome (book) wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Dominance (genetics) wikipedia , lookup
Introduction to Genetics Chapter 9 Heredity Transmission of characteristics form parents to offspring Gregor Mendel Austrian Monk Studied heredity in pea plants Studied 7 characteristics of peas Traits characteristic occur in two forms 7 Characteristics of Pea Plants Plant height (long or short) Flower Position along the stem (axial or terminal) Pod Color (green or yellow) Pod appearance (inflated or constricted) Seed texture (smooth or wrinkled) Seed color (yellow or green) Flower color (purple or white) Chromosomes Humans have 46 chromosomes arranged in 23 pairs (44 autosomes and 2 sex chromosomes) Chromosomes are made up of DNA and Proteins Chromosomes and therefore the DNA can be divided into genes Genes are short segments of DNA Chromosome with genes Allele – alternate form of a gene Example: Brown/blue, tall/short can be represented by a letter Example: Brown – B Blue - b Homologous Chromosomes Determines eye color Determines hair color Genes Blue Alleles b b One pair of your chromosomes for eye color Blue Allele b Brown Allele B One pair of your chromosomes for eye color b Blue alleles Blue Allele b b Homozygous – alleles are the same Brown Allele B Heterozygous – alleles are different Homozygous (pure) The two alleles are the same The two letters are the same BB or bb Homozygous Dominant – BB Homozygous Recessive - bb Heterozygous (hybrid) The two alleles are different The two letters are different Bb Dominant Gene A gene that will be expressed if it is present Examples – brown, tall, green, purple Written as a capital letter Recessive Gene A gene that will only be expressed if there are two alleles present Recessive genes are not expressed if there is a dominant gene present Short, blue, yellow, white Written as a lower case letter Genotype The two alleles an organism has What the genes “say” Ex. BB, Bb, bb Phenotype Physical appearance of an organism The result of the expression of the genes Example: tall, short, brown, blue The Goal The goal of genetics is to determine the possible offspring that can be produced from two parents The likelihood of an outcome is determined through the laws of probability Probability The likelihood that a specific event will occur Can be expressed as a decimal, percent or a fraction Equation for Probability Number of times an event is expected to happen Probability = The number of opportunities for an event to happen Probability Example You flip a coin once The probability of getting tails is ½ You flip a coin twice The probability of getting tails twice is 1/4 1 1 1 = X 2 2 4 First Flip H or T Second Flip If I got Tails on the first flip I can either get heads or tails On the second flip H T First Second Probability of getting: H 1/4 T 1/4 H 1/4 H T T 1/4 Gametes Egg or sperm Haploid Contains half the number of chromosomes One gene from each homologous pair Genetic Crosses When doing genetic crosses it is important to keep tract of the generations P1 – parents F1 – children of the parents (P1) F2 – Children of the F1’s GG gg Gg gg GG Gg A Genetic Cross Punnett Square – used to predict the possible outcomes of a cross AA Male produces one type of sperm with the gene A aa aa Female produces one type of egg with the gene a The Baby Elephants will be.. Aa Aa Aa Aa Monohybrid Cross a a A Aa Aa A Aa Aa How to fill in the Punnett Square Monohybrid Cross Cross where one trait is looked at Dark elephant vs. light elephant Aa Male produces two types of sperm with the gene A or a Aa Female produces two type of eggs with the gene A or a The Baby Elephants will be.. AA Aa Aa aa Genotypic Ratio Ratio of the offspring's genotypes Genotypic Ratio: 1:2:1 EE – 1 Ee – 2 ee – 1 Phenotypic Ratio Ratio of the offspring's phenotypes Phenotypic ratio: 3:1 3 – smooth 1- wrinkled Phenotypes? Genotypic Ratio? Genotypes? Phenotypic Ratio? Law of Segregation A pair of genes is segregated or separated during the formation of gametes Law of Independent Assortment Genes for different characteristics are not connected They are inherited independently Dihybrid Cross A cross between individuals that involves two pairs of contrasting traits Look at hair color and eye color at the same time Look at height and color at the same time Dihybrid Cross Punnett Square AABB AB AB AB AB aabb ab ab ab ab Sperm Egg ab AB Fertilization AB ab Genes in the fertilized egg AaBb ab ab ab ab AB AaBb AaBb AaBb AaBb AB AaBb AaBb AaBb AaBb AB AaBb AaBb AaBb AaBb AaBb AaBb AaBb AaBb AB AaBb Genotypic Ratio: Phenotypic Ratio: 1 1 What if the Dihybrid cross has heterozygous parents? How do you find the gametes? How to find genes for the gametes of a dihybrid cross B AB b Ab B aB b ab A a AaBb AaBb AB Ab aB ab AB Ab aB ab Dihybrid Heterozygous Cross Genotypic Ratio 1:2:1:2:4:2:1:2:1 Testcross When an individual of unknown genotype is crossed with a homozygous recessive individual B? x bb