Natural Selection
Pesticides are chemicals that are often sprayed on crops to kill plant-eating insects, preventing damage to the crops. While pesticides are effective initially, many researchers claim that any single pesticide will see reduced effectiveness in as little as ten to fifteen years. Why is this a valid hypothesis?
Insects that are naturally resistant to these pesticides will survive and reproduce, passing that trait to their offspring
What determines if two organisms are witin the same species?
They are able to mate and produce viable, fertile offspring
Describe the modern synthesis theory of evolution.
Natural selection influences genetics, resulting in evolution
Two fossils were found at different depths within a paleontology worksite; Fossil A had 33% of its original carbon-14 remaining, while Fossil B had 58%. Which of these fossils is older? Which fossil was likely dug up first?
Fossil A; Fossil B
Define aneuploidy; how does this increase genetic variation?
An individual with an abnormal number of chromosomes for that species; introduces new mutations/influences survival of the fittest (other answers may be acceptable, up to Ms. M's discretion)
The Clean Air Act lowered levels of air pollution post-industrial revolution. As a result of this, moths with a light body color were more likely to survive and reproduce. What kind of selection is this an example of?
Directional Selection
A river forms within the geographical habitat of a hare species; the separated individuals are not able to cross this river. What kind of speciation occurred?
Within one of those populations, repeated chromosomal errors continue to occur from generation to generation. What kind of speciation may this result in?
Allopatric; Sympatric
93% of a population is lost due to an infectious disease; what source of evolution would this be classified as?
Bottleneck effect
Two species with the closest connecting root on a phylogeny share a (recent/distant) common ancestor; two species with the first root on a a phylogeny share a (recent/distant) common ancestor.
Recent; distant
Identify and explain three requirements that need to be completed for pre-mRNA to become mature mRNA?
GTP Cap, poly-A tail, Splicing
Describe the handicap principle and good genes hypothesis.
Traits favorable for sexual selection may not be favorable for survival; organisms that survive with this "handicap" are seen as having "good genes" to their potential mates
What are three examples of prezygotic barriers?
Temporal, habitat, behavioral isolation
What 5 criteria need to be met in order for a population to be considered in HWE?
Large pop. size, no migration, no mutation, random mating (no sexual selection), no natural selection
Describe homologous structures vs. vestigial structures.
HS: similar structure, evolved to have different functions
VS: structures that remain through evolution, but do not seem to have a direct purpose
Synaptic signaling is an example of this category of signaling.
Paracrine
Provide examples of both diversifying and stabilizing selection.
Diversifying: Both ends of phenotypic spectrum selected for
Stabilizing: Moderate phenotype selected for
Examples up to Ms. M's discretion
Prezygotic or postzygotic barriers between organisms that cause an inability to interbreed is known as what?
Reproductive Isolation
Why is (pq) multiplied by 2 in the HW equation?
Represents the heterozygous genotype which can be expressed two ways (Bb, bB)
What is the most accurate way to determine common ancestry between two organisms?
Comparison of DNA sequences
Describe eukaryotic epigenetic control.
Histones can move along DNA to expose or block different genes to promote or prevent transcription
A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds.
What reasoning might best explain the increase in average beak size in the finch population during the drought?
Bigger beaks = better ability to crack through thick walled seeds = better chance of surviving and reproducing
If two organisms reproduce and create a zygote that either does not fully develop into an embryo, or produces unsuccessful offspring (non-fertile), what would we refer to this as?
Hybrid Inviability
Assuming a population is in HWE, what would be the equation to calculate the percentage of the population that expresses the dominant phenotype?
p2 + 2pq
Why are we theorized to be in the 6th mass extinction event at this point in time?
Humans are doing irreversible damage to natural ecosystems; species are becoming endangered and extinct at an extremely rapid rate.
Explain the function of the trp operon when tryptophan is present vs. when tryptophan is absent.
Trp present = repressor bound to operator, transcription does not occur, expression is silenced
Trp absent = repressor free, RNA Pol can bind and transcribe, expression turned on