Flashcards in Chapter 9 Deck (40):
major abiotic and biotic factors that tend to increase or decrease the population size and age and sex composition of a species.
number of individuals in a certain space.
the proportion of individuals of each age in a population
when a species stay in tight packs.
all the species have an equal space between them.
when a species is distributed unevenly in an area.
migration of a species into a country or area to take up permeant residence
when a species leaves their native country and goes to live somewhere else.
organisms that are not mature enough to reproduce.
organisms that are capable of reproduction
post reproductive stage
and organisms that are too old to reproduce.
maximum rate at which the population of a given species can increase when there are no limits on its rate.
intrinsic rate of increase
rate at which a population could grow if it had unlimited resources.
all the limiting factors that act together to limit the growth of a population.
maximum population of a particular species that a given habitat can support over a given period.
pattern in which exponential population growth occurs when the population is small, and the population growth decreases steadily with time as the population approaches the carrying capacity.
growth in which some quantity, such as population size or economic output, increases at a constant rate per unit of time (such as 2% per year). Ex: 2, 4, 8, 16, 32, 64 and so on; when the increase in quantity over time is plotted, this type of growth yields a curve shaped like a J.
leveling off of an exponential, J-shaped curve when a rapidly growing population exceeds the carrying capacity of its environment and ceases to grow.
organisms use up their resource supplies and temporarily exceed the carrying capacity of the environment.
reproductive time lag
the period need for the birth rate to fall and the death rate to rise in response to resource overconsumption.
sharp reduction in the population of a species when its numbers exceed the carrying capacity of its habitat.
density-independent population control
affects a population's size regardless of its density. ex: flood
density-dependent population control
factors that limit population growth have a greater effect as a population's density increase. ex: no food
a species whose population size is said to have a fairly stable population size.
their population growth may occasionally explode, to a high peak and then crash to a more stable lower level or in some cases a very level.
population size over a regular time period, populations rise and fall.
some populations appear to have irregular behavior in their changes in population sir, with no recurring pattern.
reproduction in which a mother cell divides to produce two identical daughter cells that are clones of the mother cell. this type of reproduction is common in single-celled organisms.
species with a capacity for a high rate of population increase (r). have many, usually small offspring and give them little or no parental care or protection.
species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age.
graph showing the number of survivors in different age groups for a particular species.
a population that typically has high survivorship to a certain age , then high mortality.
a population survivorship is low early in life.
a population shows fairly constant death rate at all ages.
when a few individuals in a population colonize a new habitat that is geographically isolated from other members of the population.
occurs when only a few individuals in a population survive a catastrophe such as a fire of hurricane.
involves random changes in the gene frequencies in a population that can lead to unequal reproductive success.
occurs when individuals in a small population mate with one one another.
mobile populations that are geographically separated from one another can exchange genes when some of their members get together occasionally and mate.