Bio 250 Simu text notes (exam #1???) Already Answered Questions Graded A+.

The theory of evolution - correct answer -is the conceptual foundation of all life sciences -"nothing in biology makes sense except in the light of evolution" Ecologists - correct answer study processes that relate to how organisms interact with each other and their environment, which includes population growth, nutrient cycling, competition, herbivory and predation; might ask what sticklebacks eat, what predators they have, and how they compete with other fish in the lake Evolutionary biologists - correct answer study the processes that lead to change in the genetic composition of populations over generations, which includes speciation, extinction and adaption; for example, might look at a stickleback and ask how it came to be heavily armored with bony plates, or might ask why a stickleback from one lake looks different from sticklebacks in other lakes Biologists - correct answer used to think that evolutionary and ecological processes happen on such different time scales that the two fields of study need not be too concerned with each other Evolution - correct answer -was responsible for producing the organisms ecologists study, but no measurable evolutionary changes were going to happen while an ecologists was watching -can be startlingly fast, often occurring within a few generations -often facilitated by ecological processes, and the ecological impacts that result can be profound -is a change in the genetic composition of a population from one generation to the next -consists of changes from one generation to the next in the frequencies of alleles Methods for controlling pink bollworm outbreaks - correct answer setting traps baited with pheromones, sterilization, and spraying fields with chemical insecticides Chemical insecticides - correct answer -when properly used can be effective -carry serious drawbacks -toxic to humans and other animals -expensive -kill beneficial arthropods, including predators that are natural enemies of the pink bollworm and other crop pests Bollgard - correct answer -1996 commercial debut of a new weapon to fight against bollworms -is a cotton variety genetically engineered to produce its own biological insecticide -developed it from a bacterium called Bacillus thuringiensis or Bt for short -encodes a protein called Bt toxin Cry1Ac Bt toxin Cry1Ac - correct answer -toxin -harmless to most animals, but poisonous to the larvae of butterflies and moths -if caterpillar swallows it, in membranes of the midgut cells and kills it -much less susceptible to infestation by pink bollworms 2 conclusions from Tabashniks research - correct answer 1-pink bollworm populations are capable of evolving resistance to Bt toxin 2-(at least under the right circumstances) populations can evolve very quickly Rapid evolution - correct answer common in nature and is often facilitated by ecological phenomena such as predation ex=fish population in Lake Washington Eutrophic - correct answer describes a lake with a high level of productivity Sticklebacks - correct answer -threespine ones live in Lake Washington -prey to cutthroat trout -not entirely defenseless -have bony plates in their skin that serve as armor -some wear a complete set of armor plating, some wear a partial set and some wear a minimal set -more armor plating gives better protection against the trout but this comes at a cost -tend to be more heavily armored in lakes and streams where they are more vulnerable to attack by predatory fish and less heavily armored where they are less vulnerable Completely armored sticklebacks - correct answer -grow more slowly -survive the winter at lower rates -breed later -more vulnerable to predatory insects that eat juvenile fish Take home message from stickleback investigation - correct answer -populations in nature can evolve rapidly enough to change the ecological interactions between species -focused on evolution by natural selection, but it actually involves multiple different mechanisms of evolution, all of which can be happening at the same time Mechanisms of Evolution - correct answer -natural selection, migration, mutation and genetic drift -can occur simultaneously within a single population but they can also interact in interesting and ecologically relevant ways -one can facilitate or hinder by another Example of migration - correct answer some blue simploids cross a mountain range, leaving one population and joining another Example of genetic drift - correct answer one breeding season, just by random chance, yellow Simploids have more offspring than blue Simploids do Example of mutation - correct answer a genetic change occurs during reproduction, introducing green as a new color Example of natural selection - correct answer yellow Simploids can get sun sickness, a recent increase in sun exposure raises their mortality Trade-offs - correct answer alternative that must be given up when one choice is made rather than another Evolution and ecology are intertwined... - correct answer evolution is often facilitated by ecological processes and the resulting impacts can be ecologically important Evolution by natural selection - correct answer happens when individuals with certain traits survive and reproduce at higher rates than others Darwin 2 conclusions - correct answer 1-Earths organisms are descended with modification from common ancestors 2-the process largely responsible is evolution by natural selection Theory of evolution by natural selection 3 requirements - correct answer 1-everybody is different 2-at least some of the differences among individuals are passed genetically from parents to offspring; in other words the trait must be heritable which means offspring resemble their parents 3-individuals with certain traits survive and reproduce at higher rates than those with other traits Reproductive success is non-random... - correct answer this difference in reproductive success may not seem like much at first glance, but even a small advantage can over many generations lead to evolution Population genetics - correct answer -study of allele frequency distribution and change under the influence of evolutionary processes -interested in genetic differences within and between populations as well as how the genetic composition of populations changes over time and how new species come to be Common - correct answer traits associated with survival and reproduction become Rare - correct answer traits associated with early death and reproductive failure become DNA - correct answer -hereditary info is carried by this -provides instructions for building proteins Requirement 1 - correct answer individuals vary in phenotype, that is they look, function and act differently Requirement 2 - correct answer differences in phenotype are at least partly due to differences in genotype, that is some variation among individuals arises because they carry different alleles for their genes, which are passed to them from their parents Requirement 3 - correct answer some phenotypes, and thus some genotypes, survive and reproduce at higher rates than others The automatic consequence - correct answer the relative abundance of genotypes and thus the alleles that comprise them, change from one generation to the next Eda - correct answer -the variation in body armor in sticklebacks is largely though not entirely controlled by alleles of a gene called this -encodes a protein called ectodysplasin Ectodysplasin - correct answer -made and secreted by cells as a means of sending signals to each other -in mammals, messages in the form of this play a role in the development of a variety of structures that arise from the skin including hair, teeth, sweat glands and dermal bones Different phenotypes and thus different genotypes... - correct answer are more likely to survive and reproduce in different habitats Frequency - correct answer another term for relative abundance Monitoring genotype and allele frequencies is an effective way... - correct answer to determine whether the stickleback population is evolving Quantative traits - correct answer traits are continuous, rather than discrete, distributions are called this Variation for most quantitative traits is due... - correct answer to differences in genes passed from parents to offspring, the theory of evolution applies, the theory applies to all heritable traits Natural selection - correct answer is a universal process that will cause allele frequencies to change for any population meeting the requirements Adaption - correct answer is a trait that has evolved by natural selection and therefore increases an individuals chances of surviving and reproducing relative to other individuals, that is, increases the individuals fitness Local adaption - correct answer occurs when individuals in a population carry adaptions specific to their local environment Important consequence of local adaption - correct answer is that individuals transplanted from other areas have lower fitness than the locally adapted natives Reciprocal transplant experiments - correct answer in these experiments, individuals from populations in different environments are reared in their non-native environments to determine if the trait in question is a local adaption Sampling error - correct answer arises from randomness Genetic drift - correct answer -evolution that occurs as a result of sampling error -can occur in various ways, any time survival and reproduction are subject to chance Founder effect - correct answer particular form of genetic drift that you have discovered here is sampling error that occurs during the establishment of new populations Migration - correct answer is a mechanism of evolution, can act as a single even that changes allele frequencies suddenly and these changes impact future generations as time unfolds 3 mechanisms of evolution (that are relevant in ecological contexts) - correct answer natural selection, genetic drift and migration Theory of evolution - correct answer can be framed in the language of modern genetics Process of science - correct answer includes both observational studies as well as experiments Observational studies - correct answer can suggest associations between 2 variables but they cannot establish that change in one variable causes the change in the other, the association may exist because both variables are affected by a third factor that was not observed Well-designed experiments includes - correct answer -independent or treatment variables (experimental group, control group) -potentially confounding variables -dependent or outcome variables Independent or treatment, variables - correct answer one or more likely causal variables that you