Bio 14: Organisms and Populations - First Exam
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- Predict what a person with type I diabetes mellitus should do when the blood-glucose level is too high and when it is too low.
- These people cannot produce insulin because their immune system has destroyed the pancreatic cells that make insulin. If their blood level is too high, they should inject insulin so it can absorb the glucose, if it is too low, they should eat something with high concentration of sugar to increase their glucose levels quickly.
- What are the four conditions that need to be met for a population to experience natural selection?
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1) Individuals vary in their traits
2) some of these variations are heritable
3)some individuals survive and reproduce better than other individuals
4)differential survival and reproduction(DARWINIAN FITNESS) is influenced by the heritable traits of individuals. - Evolution
- Genetically based change in a population's traits over time.**A change in a population's allele frequency over time.
- Adaptations
- Heritable traits that increase an individual's fitness relative to individuals lacking that trait.
- Darwinian Fitness
- A relative measure in which groups (or genotypes) are compared.
- Explain how the rpoB gene in M. Tuberculosis mutated and adapted to survive antibiotic.
- When antibiotics were administered to the patient, they did not kill all the rpoB genes. The alleles that survived had a huge selective advantage, they survived better without mutation and reproduced.
- Give an example of adaptation in a population.
- The Galapagos finches. After a large drout, the finches that survived were those with large deep beaks because they were able to eat tough fruits. The large, deep beak is an adaptation for cracking large, tlough fruits and seeds.
- Give a definiton of inbreeding and an example.
- Inbreeding is mating between relatives--any kind of mating between relatives. An example is the intermarriage between the royal families of Europe.
- Positive Assortative Mating
- Mating between similar phenotypes, not necessarily relatives. For example, tall people marrying each other.
- Negative Assortative Mating
- Mating between dissimilar phenotypes.
- Sexual Dimorphism
- Refers to when the two sexes have different physical appearance (two morphs).Example: Elephant seals show a big size difference between females and males.
- What are the consequences of cross-pollination versus those of self-pollination?
- Cross pollination leads to outcrossing, in which male and female gametes are exchanged between different individuals of the same species. Self-pollination, in contrast, leads to self-fertizlization. Selfing is the most extreme form of inbreeding.
- Some flowers are self-incompatible, what does this mean?
- They have sophisticated mechanisms to enforce outcrossing.
- Competition
- Occurs when individuals use the same resources and when those resources are limited.
- Mimicry
- Takes place when one species resembles another
- Mullerian Mimicry
- Occurs when harmful species resemble each other. Example: bright colored wasps
- Batesian mimicry
- Occurs when a harmless species resembles a harmful one. Example:Monarch butterfly and Viceroy (mimiquer)
- Mutualism
- Are positive interactions that involve a wide variety of organisms and rewards.
- Kinds of Mutualisms
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defense-food
harvesting-food
gamete transfer - Examples of Mutualisms
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-Pollinator attractants produced by plants
-animal dispersal of seeds
-deceiving individuals of another species - Allopatric
- Populations that are isolated because physical barriers prevent them.
- Sympatric
- Genetic isolation that occurs if somehting prevents the population from successfully interbreeding. (sympatric-live in same geographical area).
- Zygote
- a fertilized ovum; prezygotic mechanisms prevent different populations from producing zygotes; postzygotic mechanisms prevent zyogte from maturing and/or producing offspring (horse and donkey)
- Speciation
- The creation of new species caused by genetic divergence: populations that experience reduced gene flow may diverge genetica due to a mutation, genetic drift, and/or natural selection
- Species
- A distinct type of organism, formally defined as an evolutionarily independent population. EVOLUTIONARY INDEPENDENCE BEGINS WITH LACK OF GENE FLOW; once gene flow stops, mutation,selection,and drift can act on these independent populations
- Biological speices concept
- Evaluates difference by determining if two populations are able to successfully interbreed.
- Morphospecies Concept
- Relies on difference in appearance
- Phylogenetic Species Concept
- Uses phylogenetic trees to evaluate evolutionary independence
- Genetic Divergence
- Refers to differences between populations within a species, or difference between lineages that are becoming species
- Genetic Variation
- Refers to ideas like how many allele are at a locus, whether there are lots of loci that have more than 1 allele, whether there are heterozygotes in the population for some loci--it is a within-population idea
- Allopatric Speciation
- Reduction or elimination of gene flow due to physical isolation
- Sympatry
- Populations or species that live in the sam geographic region (close enough to mate)
- Polyploide
- The presence of more than two sets of chromosomes; causes speciation in sympatric plant populations
- Autopolyploid
- Mutations that result in a doubling of chromosome number
- Allopolyploid
- Individuals are produced by a mating between parents of two different species
- Adaptive Radiation
- When a single lineage produces many descendant groups in ashort period of time. Usually occur when habitats are unoccupied by competitors.
- What are some examples of traits that allowed exploitation of new habitats, causing adaptive radiations?
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1) the evolution of wings, three pairs of legs, and a protective external skeleton in insects
2)the evolution of flowers in angiosperms
3)the evolution of feathers and wings in birds
4)the evolution of a second set of jaws in cichlid fish.