Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Biology 191 Lect. 2
Biology 191 Lecture 2, Exam 1 Study
| Question | Answer |
|---|---|
| State four documented cases of evolution | 1. Drug resistance in HIV<br />2. Industrial melanism in moths<br />3. Sickle Cell anemia allele in A.A. <br />4. Antibiotic resistance in bacteria |
| Falsifiability | Karl Popper's test for scientific validity: to be considered scientific, a theory must be constructed in such a way that it is capable of being disproved |
| Which evolves: pop or individuals | Populations |
| Population | a group of individuals in a particular place that are capable of interbreeding |
| subpopulation, deme, mendelian population | a locally interbreeding group within a geographic population |
| gene pool | the sum total of genetic information present in a population at any given time |
| genotype frequency | the relative porportion of a particular genotype (# from 0 to 1) |
| Allele Frequency | relative proportion of an aleele at a particular gene locus (# from 0 to 1) |
| Formula for calculating allele frequency, result | q = (NAa + 0.5Naa)/N; for two alleles, p + q = 1<br /> Result: 2 populations with very different genotype frequencies can have the same allele frequencies |
| diploid | 2 alleles at each loci (humans are diploid) |
| Hardy-Weinberg Theorem | Specifies the conditions that must be met for the pop. to remain at equilibrium<br /> - no mutation<br /> - large pop. <br /> - random mating <br /> - no migration into/out of pop./ NO GENE FLOW <br /> - All genotypes survive and rep. =ly well (no select) |
| Given freq of aa, calculate AA, Aa genogype | p^2 + 2pq + q^2 = 1 (take 1/10000, square root to find p. Subtract p from 1 to find q) |
| Agents of Evolutionary Change | - Mutation <br /> - Genetic Drift <br /> - Non-random mating <br /> - gene flow (migration) <br /> - selection (sexual and natural) |
| mutations | any change in DNA sequence, from single base substitutions to deletion or addition of tens or hundreds of bases, to duplication or reorganization of entire chromosomes; ultimate source of genetic variation but usually low in rate |
| Transposable elements | Category of non-coding DNA. Parasitic, selfish genetic elements that accumulate by transposition (copying themselves to new locations in the genome |
| Mutations caused by Transposable elements (4) | - inserting into protein-coding genes <br /> - inserting into regulatory sequences <br /> - carrying segments of host DNA sequences to new locations in genome <br /> - hindering precise chromosomal pairing during cell division |
| 45% of human genome is transposable element sequence | (blank) |
| horizontal transfer(2 ways) | gene transfer from one species to another. 3 ways <br />- conjugation (temporary joining of two bacterial cells and one-way transfer of DNA from donor to recipient using sex pilus) <br />- transformation take up dna from surrounding environment |
| horizontal transfer(1 way) | transduction- transfer of genes from one bacterium to another with bacterial virus acting as carrier of the genes |
| Traits acquired through horizontal transfer: | new metabolic capacities, virulence and antibiotic resistance |
| Conjugative transposons: | horizontal transfer of virulence and antibiotic resistance in CDiff |
| Genetic drift: | changes in allele frequencies due to chance; most important in small populations. <br /> bottleneck , Founder Effect |
| bottleneck Effect | type of genetic drift. Sudden change in environment may drastically reduce population size resulting in change in allele frequencies & potential loss of alleles. Bottlenecks have eliminated genetic variation in some species |
| founder effect | type of genetic drift: when a new population is started by a few members of the original population. Can result in reduced genetic variation compared to orig. population and non-random sample of alleles in original population |
| Founder effect examples | - Tristan de Cunha, british settlement founded by 15 colonists in 1814. they have a high incidence of retenitis pigmentosa (10x higher frequency in Tdec than in Britain)<br /> - Amish of Penn. descended from 200 ppl, suffer higher rates of Ellis-van Crev |
| Non-random mating: | inbreeding (depresses fitness, higher mortality rates, excess of homozygotes),<br /> assortative mating (similar phenotypes mate preferentially, increase homozygosity)<br /> disassortative mating - dissimilar mate pref., increases heter. imp at MHC loci |
| Gene Flow | Movement of aleeles from one pop. to another by (1) migration of fertile indiv. (2) mating of indiv. in adjacent pop. <br /> - Tends to reduce differences in allele freq. between pop. over time. Can oppose natural selection and reduce local adaptation |
| benefits of Gene flow | - restoration of lost alleles through genetic drift <br /> - introduction of new, beneficial alleles |
| Natural Selection (vs sexual) | the superior survival and /or reproduction of some phenotypic variants compared to others under the environmental conditions that prevail at the time |
| Sexual selection (vs natural) | differential reproductive success resulting from competition between members of one sex, usually males, to achieve matings and/or fertilizations ( can result in evolution of exaggerated male traits determental to survival) |
| Selection acts on phenotype of individual and indirectly adapts population to itsenvironment by increasing or maintaining favorable genotypes in gene pool | (blank) |
| Difference between natural selection and evolution by natural selection | Natural selection will not produce evolutionary change in a pop. unless phenotypes differ in their genotypes (variation must have genetic basis) |
| What is different about natural selection as an evolutionary force? | - N.S. produces adaptations that + the ability of individ. to survive/repord. in particular environ. (comp. to others lacking traits) vs. other evo. forces can cause maladaptation<br /> - causes allele frequency changes that proceed indep. at diff loci |
Created by:
analeah
Popular Biology sets