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hartmanexam4
ch 18,19,20,21
| Question | Answer |
|---|---|
| population | A group of individuals belonging to the same species, occupying the same given area. |
| Populations _______ , __________ do not. | Populations evolve, individuals do not. |
| Dimorphism | Two variations of a trait in a population. |
| Polymorphism | Three or more variations in a trait. |
| Offspring inherit ______, not ________. | Offspring inherit GENOTYPES not PHENOTYPES. |
| Five factors of alleles... | 1. Crossing over & genetic recombination = in meiosis 2. Ind. Assortment of chromosomes occuring in meiosis. 3. Fertilization btwn gen. varied gametes = new comb of genes 4. Gene mutations create new alleles. 5. Ab. Changes in chrom struct/# |
| Mutations | -Heritable changes in DNA that can alter gene expression. -Random, with a phenotypic outcome = neutral, beneficial, harmful, lethal. |
| The only source of new alleles.. | Mutations. - The genetic foundation for biological diversity. |
| Allele frequencies.. | A measure of the abundance of each kind of allele in the entire population. |
| Evolution can be detected by.. | Change in allege frequencies from the genetic equilibrium of a population. |
| 5 conditions for STABLE POPULATION (no evolution) | 1. No mutations occur 2. Very large population (infinite) 3. Population is isolated from other populations of same species 4. All members survive, mate, & reproduce 5. Mating is random |
| MICROEVOLUTION | *The change is allele frequencies brought about by mutation, genetic drift, gene flow, & natural selection.* -The change of allele frequency over time, can be mathematically demonstrated. |
| Hardy-Weinberg Equilibrium Equation | p^2 + 2pq + q^2 = 1 |
| Researchers use the Hardy-Weinburg equation to.. | Estimate the frequency of carriers of alleles that cause genetic disorders and traits. |
| Natural Selection | May be the most influential microevolutionary process. |
| Three major categories of selection (NS) | Directional, Stabilizing, Disruptive. |
| Sexual dimorphism | Most species having distinctively male and female phenotypes. |
| Sexual Selection | Based on any trait that gives the individual a competitive edge in MATING and PRODUCING OFFSPRING. |
| Genetic Drift | The RANDOM FLUCTUATION in allele frequencies over time, due to chance occurrences alone. |
| Genetic Drift is ... (4) | 1. More significant in small pop's bc of small #'s in pop 2. Increases chance of any allele becoming more or less prevalent 3. May lead to a HOMOZYGOUS condition in most pop's 4. FIXATION - one kind of allele remains at specified locus in pop |
| Bottleneck | Some STRESSFUL situation greatly reduces the size of a population, leaving few (typical/atypical) individuals to reestablish the pop. -Decreases genetic diversity & can be cause of genetic drift. |
| Founder effect | A few individuals leave the original population to establish a new one. -Bc only founders provide for the gene pool of the pop, the diversity is LIMITED. |
| Inbreeding | Nonrandom mating btwn closely related individuals. -Tends to increase HOMOZYGOUS condition. -leading to lower potential fitness & survival rates (lack of genetic diversity) |
| Gene Flow | Genes moving in (immigration) or out (emigration) of populations with individuals. |
| Pre-Zygotic Isolation Mechanisms | Temporal, Mechanical, Behavioral, Ecological, Gamete |
| Post-Zygotic Isolation Mechanisms | Hybrid Inviability- Fert occurs, zygote fails to develop. Hybrid Sterility- Fert produces sterile offspring. |
| Allopatric Speciation | (thought to be most common form of speciation) Occurs when a species becomes separated by a physical barrier - thus, halting gene flow between two populations - eventually leading to REPRODUCTIVE ISOLATION. |
| Sympatric speciation | Divergence within the same home range of a species. |
| Polyploidy | A result of nondisjunction during cell division that can lead to a change in chromosome number. |
| Parapatric speciation | When one pop extends across a large, diverse habitat. Exert selection pressures on parts of the pop - may result in divergences leading to speciation. Hybrids forming in contact zone btwn habitats are typically LESS FIT than ones on either side. |
| MACROEVOLUTION | -occurs at the level of a population -occurs at a much larger scale |
| coevolution | Reasoning that close ecological interactions btwn 2 species cause them to evolve jointly. |
| Stasis | Idea that species can have a long-term lineage with relatively little evolutionary change. |
| Pre-Adaptation | Describes the appearance of a trait that was originally used for something else. |
| Adaptive Radiation | Des a dramatic INCREASE in new species due to presence of many new niches to fill in a habitat. -May be in response to development of a single novel trait, or loss os species previously filling the niches. |
| Extinction | Losses of many lineages. More than 20 mass extinctions on earth - each mass extinction is followed by period of ADAPTIVE RADIATION. |
| Population Density | Number of individuals per a certain area. |
| Population distribution | Where the individuals are positioned in a certain area. |
| Capture-recapture method | (to estimate the size of a population of animals) 1. Sample size must be large enough to gather significant info 2. Animals captured must have no bias (easier/more difficult to catch) |
| "Per capita growth rate" | birth rate - death rate = pcgr more than 0 = pop exponential growth, rep by J-shaped curve |
| "biotic potential" | indicates largest amount of increase that can occur in that particular pop. |
| Carrying capacity | Largest # of individuals that a certain environment can support; S-shaped curve rep how a pop naturally changes. |
| Density Dependent factors | Become more critical as the pop increases. ( food, water, disease) |
| Density Independent factors | Not influenced by the size of the pop. (flood, fires, earthquakes) |
| Life tables | Illustrate the # of individuals that survive in various age categories. |
| Survivorship curve | A visual representation of the age-specific survival of a population. |
| Human populations current rate of increase... | approximately 1.2% |
| Rate of growth is due to.. | 1. New Habitats - humans can spread easily to new places. 2. New technology- increase carrying capacity of environment 3. Overcome limiting factors - combat many diseases |
| Total fertility rate | The average # of children born to each woman of reproductive age. |
| Fertility rate worldwide.. | DECREASED from 6.5 to 2.7 (children) in the past 50 years. (1/3 of pop not yet of reproductive age) |
| Community | All the populations of all species in a given habitat. |
| Population | A group of individuals of the same species in the same area. |
| Species | A type of organism (can mate and produce fertile offspring.) |
| Habitat | A place where an organism lives; described by physical and chemical features and an array of species. |
| Niche | The role of a species within a community. |
| Commensalism | A relationship where one species in BENEFITED and the other is UNAFFECTED. |
| Mutualism | Relationship where BOTH species are BENEFITED. |
| Interspecific competition | HURTS BOTH species. |
| Parasitism | HELPS one species at the other species expense. |
| Competitive Exclusion | When 2 species require the same limited resource to survive or reproduce, the better competitor will drive the other to extinction. (can coexist if requirements aren't identical) |
| Parasitoid | Parasite that lays eggs in an insects body and destroys it. |
| ecosystem | the sum of the organisms and their physical environment, all interacting through a one-way flow of energy and a cycling of nutrients. an open system - requires ongoing inputs of energy and/or nutrients to endure. |
| primary producer | the plant that serves an autotroph by harnessing the sun's energy. |
| consumer | the animal or HETEROTROPH that derives energy from consuming the plant or other animals. |
| detritivore | an animal that consumes debris and small bits of organic matter. |
| decomposer | eats the wastes and the remains of plants and animals. |
| Food Chain | represents the passage of energy from one trophic level to the next. |
| Food Web | A complex interaction among many species of the ecosystem. |
| Grazing food chain | energy goes from PRODUCERS to CONSUMERS |
| Detrital food chain | energy goes from PRODUCERS to DETRITIVORES & DECOMPOSERS |
| Primary production | the rate at which plants harness the suns energy. Depends on the availability of water and nutrients. Higher on land than in water. |
| Biomass pyramid | used as a tool to represent the dry weight of the organisms at each trophic level. -plants/producers make up the base -consumers = upper portion -largest carnivores at the very top |
| energy pyramid | helps to show how energy is lost when transferred to each trophic level. |
| gasses contributing to greenhouse effect | CO2, H2O, N20 (nitrous oxide), CH4(methane), CFC's (chlorofluorocarbons) |
| N2 | nitrogen gas |
| NH3 | ammonia |
| NH4 | ammonium |
| NO2 | nitrite |
| NO3 | nitrate |
| HNO3 | nitric oxide |
| convert N2 to usable form | lightening, volcanoes, bacteria |
| nitrogen fixation | the process by which bacteria breaks all three bond of atmospheric N2 and incorporates the N atoms into NH3. |
| Ammonification | the process by which bacteria and fungi break apart proteins and other N- containing molecules and produce ammonia. |
| Nitrification | begins when bacteria convert NH4 to NO2 and other nitrifying bacteria then use the NO2 in reactions that end with the formation of NO3. |
| Denitrification | the process by which bacteria convert NO2 or NO3 back to atmospheric nitrogen. |
Created by:
bgodbey
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