BS 110 Quiz 4
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- What are the natural selection postulates?
- individuals in a population vary, variations are heritable, competition for survival, and variation affects survivability
- What does the mode of natural selection depend on?
- the selective agent
- Besides directional selection what are the other two modes of natural selection?
- disruptive and stabilizing selection
- What is disruptive selection?
- the homozygous traits are favored (have a higher fitness)
- What is stabilizing selection?
- the heterozygous traits are favored over the homozygous traits (have a higher fitness)
- What is genetic drift?
- a change in allele frequencies due to random events in the environment
- What is the founder effect?
- When a subset of a population becomes permanently separated from the original population
- What size of population are more susceptible to genetics drift?
- small populations
- What are the problems associated with the loss of heterozygosity?
- All individuals in a population equally susceptible to pathogens and there is no variation in a population for natural selection to act upon
- What is migration?
- gene flow between populations
- What causes migration and give some examples?
- Anything that moves alleles such as dispersal or pollen
- What do you call the group into which an individual is born?
- natal
- Migration tends to do what to populations?
- homogenize them
- Migration may be opposed to what?
- selection
- What does the biological species concept state?
- That populations of orgainsms capable of interbreeding and producing viable, fertile offspring
- What is divergence?
- accumulation of genetic change over time
- When does speciation occur?
- when two populations of an original population can no longer interbreed
- What is the original hypothesis for how speciation occurs?
- Allopatric speciation
- What does alloparty mean?
- living in different areas
- What are the three steps to allopatric speciation?
- Isolation, Divergence,and Reproductive Isolation
- What is isolation?
- When something like geographic separation occurs or a new habitat is colonized
- What is reinforcement?
- when hybrids are unified
- What are pre-zygomatic barriers and give some example?
- they impede reproduction or fertilization such as temporal, habitat, behavioral, and mechanical (round hole square peg)
- What are some post-zygomatic barriers?
- hybrid inviability or sterility
- What is sympatric speciation?
- when organisms of the same populations live in different habitats (african fish living on different depths of water)
- Who divided living things into plants and animals more than 2000 years ago?
- Aristotle
- Who in 1750 instituted the use of binomial nomenclature?
- Carolus Linnaeus
- What word in a species name is always capitalized?
- genus
- What word in a species name is always lower case?
- species
- What is the linnaean hierarchy in order?
- domain, kingdom, phylum, class, order, family, genus, and species