bio 117 Exam 1 | Questions & 100% Correct Answers (Verified) | Latest Update | Grade A+

bio 117 Exam 1 | Questions & 100% Correct Answers (Verified) | Latest Update | Grade A+ evolution Correct Answer: a change in a population over time Natural selection Correct Answer: the process by which populations change over time What is necessary for natural selection to occur? Correct Answer: traits within a population vary -some individuals leave more offspring than others (fitness) Mechanisms of evolutionary change Correct Answer: Natural selection, genetic drift, gene flow and mutation Fitness Correct Answer: the ability of an individual to produce offspring relative to others of the same species 2 Types of selection Correct Answer: directional, stabilizing and disruptive Directional selection Correct Answer: the result after selection will be one extreme or the other stabilizing selection Correct Answer: the result after selection will be a median phenotype disruptive selection Correct Answer: the median has the lowest fitness and the two extremes have the highest (graph will look like camel humps) Genetic drift Correct Answer: cause change randomly -can lead to an increase in the frequency of alleles that decrease fitness (meaning something that original would have been the higher fitness no longer is) -two components: founder and bottleneck Founder effect Correct Answer: begin with a large varied population; then a random sampling of a few individuals leave and establish a new population 3 -not all variation will be in new generation Bottleneck effect Correct Answer: a large population; a few randomly start a new population; death eliminates the original population Gene flow Correct Answer: immigration and emigration -frequencies will be vastly different that what they would have been Immigration Correct Answer: new individuals entering a population emigration Correct Answer: individuals leaving a population mutation Correct Answer: has the ability to introduce new alleles -only evolutionary change that can create something new -Change the DNA > change RNA >change protein >change trait Outcomes of mutatio