Friday, August 31, 2007

SHW - Pg. 6

6. Define carrying capacity
- The maximum population size that can be supported by the resources.

7. Write the formula for population growth with limits. Define the terms.
- dN/dt = rmaxN
The maximum growth rate for the population (rmax), called the intrinsic rate of increase.
If N represents population size, and t represents time, then DN is the change is population size and Dt is the time interval

8. What happens to a population when the number of individuals approaches carrying capacity?
- The population will have to stop growing, or individuals must die.

9. Compare K-selected to r-selected species. Give examples of each.
- K-selected: aka equilibrial populations, those that are likely to be living at a density near the limit imposed by their resources.
- r-selected: aka opportunistic populations, likely to be found in variable environments in which population densities fluctuate, or in open habitats where individuals are likely to face little competition.
-Laboratory experiments suggest that different populations of the same species may show a different balance of K-selected and r-selected traits, depending on conditions.

10. ID factors that regulate population size.
- Maturation time, lifespan, death rate, # of offspring produced per reproductive episode, # of reproductions per lifetime, timing of first reproduction, size of offspring or eggs, parental care

11. Compare density-independent and density-dependent factors limiting populations.
- Density-dependent factors have an increased effect on a population as population density increases. This is a type of negative feedback.
- Density-independent factors are unrelated to population density.

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