Unformatted text preview: Last Class Development and cancer Stem cell theory of cancer How do we know if something involves two genes or two alleles Complementation Test Determine if a variant (mutant) phenotype is at the same locus (are allelic) or occurs at a different locus (a second gene nonallelic) Mate the two individuals and test if they complement is a wild-type (normal) phenotype produced? Complementation Complementation Test Complementation: What is happening... Molecular explanation of genetic complementation What is really going on?
What Mendel theorized and what we know now What did they know? Cells There are different types Eukaryotic DNA is highly packaged with proteins Chromosomes 1865 Mendel Hereditary Unit 1900 Correns, DeVries, von Tschermak Discovered Mendels Works 1902 - Boveri and Sutton "Chromosome Theory of Heredity" 1915 Thomas Hunt Morgan "The Mechanism of Mendelian Heredity" Prokaryotic Reproduction Eukaryotic Cell Reproduction Complex Some terms used in Genetics Genotype- The genetic constitution of an organism. Phenotype- The visible appearance of an organism. Homologous chromosomes- in a diploid organism, the 2 copies of a chromosome inherited from the mother and the father. Locus- Location of a gene on a chromosome. Allelomorph (allele)- different versions of the same gene. Homozygous- the 2 copies of a gene are identical. Heterozygous- the 2 copies of a gene are different. What are alleles of a gene? Basic Structure of Chromosomes (proteins) Four basic Chromosome structures The Cell Cycle Cell Cycle The M-stage is the shortest stage. In addition to the 4 stages, two checkpoints and the 2 kinds of protein complexes (cyclin+kinase) needed to drive through the checkpoints. Mitosis
The chromosome number does not change. Two daughter cells are produced in the end. (centriole) Cytokinesis The key to any cell cycle Proper movement of the chromosomes Cohesin (glue) G1 cyclins Cyclin D
(Mitosis promotoing factor) Sexual Reproduction How do we keep chromosome numbers constant? Formation of Gametes (sperm or egg) These are haploid in chromosome number Provide genetic variation in offspring Random sorting of chromosomes Meiosis Cell Replication - Mitosis Gamete Production - Meiosis Independent Assortment Alternative alignments of paired chromosomes in metaphase I Figure 4.11 ...
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- Summer '08
- Genetics, chromosome number, Eukaryotic Cell Reproduction, gene nonallelic