GED EXAM |150 QUESTIONS WITH 100% CORRECT ANSWERS ALREADY GRADED A+.

What are Darwin's three conditions for natural selection? 1) Heritable characters 2) Characters show variation between individuals 3) Differential fitness (= survival, reproduction) between individuals What is the definition of evolution? genetic change over time in a population Is all evolution caused by natural selection? no Is natural selection the only consistent force leading to adaptations? yes What types of evidence can be gathered for evolution? Fossils Imperfection (development, bad "design") Biogeography Molecular genetics Natural selection in action Why is the left recurrent laryngeal nerve an example of bad design? distance from brain to larynx is <30cm but nerve is 1m long What is the explanation for the bad design of the left recurrent laryngeal nerve? Larynx evolved from branchial arch, innervated by 4th branch of vagus nerve Left recurrent laryngeal nerve maintained its position as function of branchial arch changed over time What are human vestigial traits? part of the body that has become functionless in the course of evolution - wisdom teeth - appendix - tail bone - body hair What is biogeography? distribution of species around the globe What are Cacti in the USA and Euphoria in South Africa an example of? convergent evolution Do animals that exhibit convergent evolution have a common ancestor of similar phenotype? no What does the cytochrome c gene and collagen extracted from Tyrannosaur vs Mammoth fossils provide evidence for? Molecular data correlates with morphological data What has happened to whales olfactory receptor genes? 68% have become pseudogenes - able to accumulate mutations without affecting survival When did mutations for the ability for human's to digest lactose appear? during development of agriculture What is neutral theory? Many DNA sequences are not genes and apparently have no function ("junk DNA") Mutations in these parts of the genome should not be selected, and should evolve randomly, as they are selectively "neutral" Natural selection does not recognise change What are endemic organisms? species native or restricted to a certain place - not found anywhere else Can natural selection occur without heritability? Yes but evolution by natural selection cannot What does LUCA stand for? last universal common ancestor How can you have a cell without DNA? - lipid protobionts can 'reproduce' and 'metabolise' - RNA can spontaneously reproduce with them What is a protobiont? precursors of prokaryotic cells What are the conditions for life? cool temperatures, gravity, water, protection from radiation What is the most probable theory for the formation of eukaryotic animal life? an archaebacterium engulfed a heterotrophic eubacterium, which eventually became mitochondria What is the most probable theory for the formation of eukaryotic plant life? autotrophic eubacterium engulfed by eukaryotic plant ancestor Was the creation of eukaryotic life a result of natural selection? no What are the possible explanations for the Cambrian explosion? Physiological change - dissolved oxygen levels allow active life-style? Geographical change - new seas and new niches? Geochemical change - sea-level changes leads to abundance of trace metals to make exoskeletons? Biological change - increase in zooplankton allows new predators to arise, increasing selection pressure? What is a species? a population of reproducing organisms that is isolated from other populations (no gene flow) How can species appear? In time along a lineage (e.g. humans/chimps and our common ancestor) In space due to isolation (e.g. animals on an island) Various genetic effects (selection, drift, bottle-necks) What are allopatric and sympatric speciation? Allopatric: speciation taking place due to separation of geological environment Sympatric: speciation occuring within the same geological environment Why is vichera unique? sexually reproducing polyploid Does genetic drift occur in small or large populations? small What are the three types of prezygotic pre-mating isolation? habitat, temporal, behavioural What are the two types of prezygotic post-mating isolation? mechanical, gametic What are the three types of post-zygotic isolation? reduced hybrid viability, reduced hybrid fertility, hybrid breakdown What are the possible outcomes of hybrid zones? reinforcement, fusion, stability What is fitness? The relative probability of survival and reproduction for a given genotype Does fitness vary according to environmental conditions? yes What explains why some characters appear to be maladaptive reducing fitness? sexual selection What is altruism? The behaviour of an animal that benefits another at its own expense What is Hamilton's rule? Natural selection of genes that lead to social actions via the sharing of these genes between performer and recipient What is Hamilton's equation for altruism? rb>c r=relatedness b=benefit c=cost What is microevolution? changes in the gene pool over time What can population genetics tell us? - How human pathogens are evolving - How much genetic diversity is present in a population - The response of the population to change - The genetic structure of a population What is the Hardy-Weinburg equilibrium equation? p^2 + 2pq +q^2 = 1 What conditions are necessary for the Hardy-Weinburg equilibrium to occur? Population size is large Mating is random No migration from other populations No selection No mutation What factors can lead to changes in allele and genotype frequencies? - Genetic drift - non-random mating - migration/gene flow - selection How is genetic variation preserved? Natural selection - Balancing selection: Heterozygote advantage - Frequency dependent selection - Different selective pressures across the geographic range of the population