BAC121 Lecture Notes - Zygote, Dna Replication, Mutation
Document Summary
Mode (most frequent) = median (mid) = mean (average value) Bell-shaped/ even distributions of values above and below mean. Standard deviation ( : measure of the spread of results about the mean of a normal distribution curve, thinner bell-shape / smaller standard deviation / less variation, same pattern with bigger bell-shape. Independent assortment of bivalents at the equator during anaphase i. Chromosomes of bivalents pulled to opposite poles at random. 2n different combinations of chromosomes in four haploid cells produced where n is the haploid number of chromosomes. Crossing over between non-sister chromatids during prophase i. At synapsis, non-sister chromatids of homologous pairs cross over at chiasmata. Homologous chromatids (corresponding pieces of genetic material) break and exchange equivalent segments between maternal and paternal chromatids. Results in new combination of genes from the two parents. Gene mutation / increased by environmental factors (eg radiation) Addition / at least one base is added during dna replication.