12 09 2013 Chapter 14 Mendel s two laws of inheritance Law of independent assortment Each pair of alleles segregates independently of another pair of alleles during gamete formation Pea color and shape Law of segregation The two alleles for a heritable character segregate separate from each other during gamete formation and end up in different gametes Thus an egg or sperm only gets one of the two available alleles in the organism making the gamete For every toss of a coin the probability of getting heads is It does not matter how many times it has landed on heads or tails the probability stays the same The multiplication rule of probability we multiply the probability of one event by the probability of another event Complete dominance Phenotypes of heterozygous and homozygous dominant are indistinguishable Incomplete dominance Red crossing with white to make a pink flower Codominance Two of the same type of phenotype are exhibited at the same time Pleiotropy A gene that has multiple phenotypic effects Epistasis Two or more genes are involved in the expression of a phenotype Lab puppies Chapter 15 Specific genes are carried on specific chromosomes If a gene is carried on an X chromosome males will be more susceptible to it because they only have one X chromosome no other chromosome to mask the recessive present on the X Genetic recombination the production of offspring with combinations of traits that differ from those found in either parent Crossing over occurs during prophase 1 of Meiosis The farther apart two genes are the higher the probability that a crossover will occur between them Nondisjunction The members of a pair of homologous chromosomes do not move properly during meiosis 1 or sister chromatids fail to separate during meiosis 2 Aneuploidy Having an abnormal number of chromosomes Monosomic Missing chromosome 2n 1 Trisomic Extra chromosome 2n 1 Polyploidy Having more than 2 SETS of chromosomes o Triploidy Tetraploidy Four types of changes that can occur in from errors in meiosis 1 Deletion Chromosomal fragment is lost 2 Duplication Deleted fragment may come attached to another 3 Inversion Chromosomal fragment may attach back to the original chromosome but in the wrong order 4 Translocation Lost fragment reattaches to a non homologous chromosome chromosome Chapter 16 12 09 2013 12 09 2013
View Full Document
Unlocking...