Biol 322 Exam 4 Study Questions and Correct Answers

Genetic variation within modern humans suggests All modern humans share recent common ancestry of sub-saharan African origin; historically recognized human races represent minimal genetic divergence; genetic variation shows serial founder effects as people spread throughout the world; some Neanderthal DNA is found in most non-African peoples; there is more genetic variation within sub-Saharan African than elsewhere (all) In some species of animals that are preyed upon, we can find evidence of mimicry or false visual signals to their predators suggesting that they prey is most likely unpalatable. What is true: This requires frequency dependent selection whereby the palatable mimics are rare relative to the toxic models Coevolution Occurs between predators and prey; between parasites and hosts; between males and females of the same species (all) The leaf-cutter ant is one species of ant that participates in a beneficial mutualism with a fungal species. The female workers in the colony as well as the reproductive females are often covered with a thick whitish-gray coating, which turns out to be a bacterium that produces antibiotics. Which of the following is true regarding the function of these bacteria? They produce antibiotics, which kill parasites that grow in the fungal gardens There are thousands of different kinds of lichens, each of which is composed of one fungal species and one species of either photosynthetic algae or cyanobacteria. When species interact, as fungi and algae do in lichen, so that the interaction of the two species increases the fitness of both species, this is called: Mutualism Virulence can evolve dependent upon the transmission rates of pathogens among hosts. Which of the following is a correct statement Lowering the transmission rate of diseases can decrease their virulence In 1977 Sidney Fox tried a different approach to testing the prebiotic synthesis of biological molecules. He mixed a number of different amino acids together at a high temperature (120°C) in an environment lacking water. When he subsequently placed the mixture into water to investigate what the amino acids would form, he: Found some peptide-like structures, but the bonds between the amino acids were weak and unstable