Shown in the diagram are homologous chromosomes during prophase i of meiosis. which of the following describes the process shown? a. a mutation occurred in which the dna content of the gene is altered. b. segregation of sister chromatids has occurred. c. alleles have condensed and segregated. d. crossing-over, in which alleles are exchanged, has occurred.

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.