BIOL-UA 11 Chapter Notes -Gamete, Epistasis, Cardiovascular Disease
Document Summary
Blending theory of heredity genetic material contributed by the two parents mixes. Particulate theory of heredity the gene idea; parents pass on discrete heritable units (genes) that retain their separate identities in offspring. Alleles are caused by variations in nucleotide sequences at a specific locus: for each character, an organism inherits two copies of a gene, one from each parent. If two alleles at a locus differ, then one determines the organisms appearance; the other has no noticeable effect on the organism"s appearance. Dominant allele is expressed by the organism. Recessive allele not expressed by the organism: law of segregation the two alleles for a heritable character segregate during gamete formation and end up in different gametes. If the organism is homozygous dominant, the test-cross will produce four organisms with the dominant phenotype. If the organism is heterozygous, the test-cross will produce 2 organisms with the dominant phenotype and 2 with the recessive phenotype.
