Genotype/Phenotype
Exam 1-1
Exam 1-2
Exam 2-1
Exam 2-2
100
List two reasons different phenotypic traits can be correlated (and explain):
What is linkage disequilibrium: two genes are physically linked, and are frequently inherited together. This correlation breaks down over time-- the closer the genes are together on the chromsome, the longer the correlation lasts What is pleiotropy: one gene affects multiple phenotypic traits (the same gene does different things in different tissues or at different developmental time-points).
100
What kind of mutation (snp or indel) would cause: Transition: Transversion: Frameshift And which of these three to you expect to see the most of in a population? The fewest of?
What is Transition = SNP (A to G, or C to T) Transversion = SNP (purine to pyrimidine) Frameshift = indel (cannot be caused by SNPs) You would expect the most transitions, the fewest frameshifts
100
What's one way to tell if a trait is homologous, or convergent? (e.g. wings in bats and birds)
1) phylogenetic-- which is the more parsimonious explanation, that the trait emerged twice, or was present in the common ancestor and lost in other mammals and reptiles 2) molecular-- if you know the genes behind the trait in both species, do the sequences suggest that they are orthologs?
100
Allele frequency change across generations--what does this show? Also, name three things that could cause this
What is What is a population not in Hardy weinberg equilibrim What is drift What is selection What is mutation What is non-random mating What is gene flow
100
Accumulation of mutations in asexual populations (do to lack of recombination) is...
What is Muller's ratchet
200
Define vocab term 'antagonistic pleiotropy'
What is when a pleiotropic gene has both beneficial and disadvantageous phenotypes (for example, the gene variant responsible for both sickle cell anemia and malaria resistance)
200
Define adaptive radiation
What is "a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available and opens environmental niches" (Wikipedia)
200
In class, we went over four different methods of resolving phylogenetic trees. Name and summarize two of these methods
What is Maximum likelihood: estimates the probability of the data being produced by each possible tree, and selects the highest probability tree Bayesian: estimates most likely tree from the data (may use priors) Parsimony: estimates the tree that requires the fewest evolutionary changes Neighbor joining: measures distance between each pair of taxa, and clusters those with the smallest distance
200
How many alleles does a diploid organism have for a gene?
What is 2 alleles
200
What is the probability that an allele will fix in a population of size 2N due to drift?
What is 1/2N
300
This vocabulary term describes when a pleiotropic gene cannot reach the highest fitness state for one trait without lowering the fitness of another trait
What is adaptive conflict
300
In a phylogenetic tree, nodes represent:
What is most recent common ancestor of descendent branches
300
How do you find the root for an unrooted phylogeny
What is add an outgroup
300
Inbreeding does what to the allelic frequencies?
What is decreases percentage of heterozygotes, increases homozygosity
400
Of the different fates for duplicated genes, which would be most likely to allow an escape from adaptive conflict?
What is subfunctionalization
400
What 3 things do you need to show evolution natural selection for an adaptive trait within a population
1) show that the VARIATION for the trait is heritable 2) show that the trait confers a fitness advantage 3) show average value/frequency of the trait changes across generations
400
What are the following? 1) Individuals vary 2) Individuals pass on alleles to offspring 3) In ever generation, some individuals are more successful at surviving and reproducing than others 4) individuals most successful at surviving and reproducing are those with alleles and allelic combinations that best adapt them to their environment
What is Darwin's 4 postulates
500
one reason two duplicates of a gene might remain completely unmodified
What is selection favoring higher gene expression
500
Define Homology (as in, homologous sequences, or homologous structures/traits)
In short: identity by descent. Similarity of a trait/sequence due to inheritance from a common ancestor
500
Which of the following is the least useful for resolving phylogenetic relationships? A) synapomorphy(shared derived character unique to clade) B)pleisomorphy(shared primitive character, older than clade) C)apomorphy(evolutionary novelty)
What is B) pleisomorphy
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