Module 4 Study Guide Notes

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Module 4 Study Guide Notes

By | November 2012
Page 1 of 2
Module 4 study Guide
*Understand the role of mutation in genetics *Know what an allele is and where they come from (where they are inherited from). -Different versions of a gene that can direct the cell to produce a slightly modified form of the same product (different expression) -Locus is the specific location of a gene on a chromosome *Understand sickle-cell anemia and the advantage of the heterozygous S gene. -Abnormal form of hemoglobin that results in a collapsed red blood cells, blockage of capillaries, reduced blood flow to organs, and without treatment –death. -Both parents must have a copy of the recessive allele that causes it *Understand what polygenic traits are. -Polygenic (or continuous) traits are characteristics that have a wide range of phenotypic expressions that form a graded series -Best examples are with humans in skin, hair, and eye color. *Know who Gregor Mendel is and the importance of his research in plant genetics. -1822-1884, proposed question of heredity, studied botany physics and mathematics at University of Vienna - Investigated how physical traits could be expressed in plant

hybrids (garden peas) led to principles of inheritance -Principle of segregation (meiosis) -Recessive and dominant traits -Principle of independent assortment- the units that code different traits sort out independently of one another (random assortment) -Published findings in 1866, accepted in 1900 -Mendalian traits (discrete traits) are controlled by alleles at only one genetic locus -Described as discrete or discontinuous *Understand recessive and dominant genes/traits (know whey they are observable in the phenotype and when they are not expressed. -Lower case (recessive) vs. upper case (dominant) -Observable when one dominant is present, or two recessive. *Understand the following terms: homozygous dominant, homozygous recessive and heterozygous dominant (and the genotypes that produce them). -Homozygous-when two copies of the same allele are present...