Contemporary Issues In Biology Exam 4 (taryn_weltzin) Exam Questions and Answers

Contemporary Issues In Biology Exam 4 (taryn_weltzin) Exam Questions and Answers Natural Selection - Answer- environment determines which organisms will survive and reproduce Fruit Flies and Humans - Answer- 15,000 similar genes - cellular/molecular levels our genetic code is indistinguishable Hunter-Gatherers (Homosapiens) - Answer- lacked agricultural technology - lived in small groups instead of large populations North American Food Resources - Answer- everything except for seafood is no longer caught/grown in the wild Domestication - Answer- began 30,000 years ago - plant/animal modified from wild ancestors for use by humans Domestication vs. Taming - Answer- domestication: generation of new varieties or breeds that are different than their wild ancestors taming: suppression of wild or aggressive behavior Dogs - Answer- domesticated wolves History of Domestication - Answer- began as having more close relation with humans and later changed to being bred for different uses Agricultural Domestication - Answer- early domestication was unintentional and later domestication was conscious Domestic Crops - Answer- selected for maximum productivity with little natural pest resistance DDT - Answer- first available in 1940's and was viewed as safe to use Pesticide Resistance - Answer- pests were sensitive to DDT but those that became resistant reproduced Biomagnification - Answer- concentration of pesticides in higher levels of food chains DDT in Food Chain - Answer- DDT is more concentrated the further up the food chain - DDT is not lost in respiration Bald Eagles and DDT - Answer- ate fish high in DDT and led to their egg shells breaking easily - number of young produced was reduced EPA and DDT - Answer- banned DDT in 1972 and eagle reproduction increased Genetically Modified Crops - Answer- gene from another plant/animal inserted into agricultural plant which then forces the plant to produce the protein specified by inserted gene Advantages of GM Crops - Answer- 1) cost effective production of proteins used in vaccines 2) reduce crop damage due to pests 3) reduce use of pesticides Continental Drift - Answer- 225 million years ago Pangea began to drift apart and 65 million years ago they moved towards current positions Coevolution - Answer- species in food webs have evolved together and are dependent on the presence of each other