Genetics

 LECTURE 23 GENETICS I: GENETICS AND THE DNA SEQUENCING REVOLUTION Understand the term genetics. Genetics is the study of heredity and variation. Understand the fundamental role DNA sequence variation plays in biological variation at all levels. DNA includes information for protein synthesis, and thus the information on how to make cells as well as complex tissues. Different unicellular organisms as well as different phenotypes in organisms are derived from variation in DNA sequences. Appreciate the variety of applications of genetic technologies. Agriculture, medicine, history, etc. Understand the recent advances in DNA sequencing technology. Human Genome Project - completed in 2001; 1000 genome project (sequencing 1000 human genomes) - 2008-2012; 100 000 Britons project - finished 2019; many animal and plant genomes sequenced. Genome sequencing is now a much faster process than in the 1990s. Appreciate the large number of individual human and species-specific genome sequences now. See above.  Appreciate the variety of biological questions addressable by genetic analysis. Cancer research, tracing infectious disease outbreaks, tracking infection in a single individual, the microbiome, environmental metagenomics.

LECTURE 24 GENETICS II: GENOTYPES, PHENOTYPES, DOMINANTS, RECESSIVES, SEGREGATION AND THE ONE FACTOR CROSS Define the terms genotype and phenotype. Genotype: The combination of alleles (genetic makeup) in an organism. Phenotype: Observable traits of an organism. Explain the terms dominant, recessive, co-dominant, homozygous, heterozygous. Dominant: In the case that an organism possesses two different alleles at a locus, the allele that determines the genotype of the organism is the dominant allele. Recessive: The recessive allele determines the phenotype of the organism only in the case that two recessive alleles are present at that locus.  Co-dominant: Two different alleles both affect the phenotype in separate, indistinguishable ways. Example: the human MN blood group. Homozygous: Two of the same allele (two dominant or two recessive alleles). Heterozygous: Two different alleles (one dominant and one recessive allele, or two co-dominant alleles). Understand the terms gamete, F1, F2, one-factor cross. Gamete: Sex cells (sperm and egg) F1: First generation after the parental generation; parents are true-breeding varieties. F2: Second generation after the parental generation, offspring of the F1 generation. One-factor cross: A genetic cross using only one trait.   State Mendel's first law and understand how it relates to meiosis. Mendel's first law = the law of segregation: The two alleles for a heritable characteristic segregate during gamete formation and end up in different gametes.   Use a Punnett square to predict the genotypes of offspring from parental gametes for a one factor cross.

LECTURE 25 GENETICS III: THE TWO FACTOR CROSS, INDEPENDENT ASSORTMENT, SEX DETERMINATION, LINKAGE AND CROSSING OVER State Mendel's second law and understand how it relates to meiosis. Mendel's second law = law of independent assortment: two or more genes assort independently - that is, each pair of alleles segregates independently of each other pair of alleles - during gamete formation. (ie. Alleles from two unlinked genes assort independently during meiosis.) Use a Punnett square to predict the genotypes of offspring from parental gametes for a two factor cross.   Understand the basis of sex determination in the fruit fly, Drosophila melanogaster. XX - female, XY - male Understand the basis of sex-linkage for genes located on the sex chromosomes. Understand the segregation patterns of alleles from two physically linked genetic loci. Understand the meiotic and chromosomal basis of segregation patterns of alleles from two physically linked genetic loci. Understand the role of meiotic recombination in altering the segregation patterns of alleles from two physically linked genetic loci.