BIOL 150 Study Guide - Quiz Guide: Chordate, Double Fertilization, Vertebrate
Document Summary
Biology 130, spring 2009: third opportunity topical overview. Population density- number of individuals per square kilometer of land area. It is a common biological measurement and is more often used by conservationists as a measure than population size. Low densities may cause an extinction vortex and lead to further reduced fertility. Examples of the causes in low population densities include: increased problems with locating mates & increased inbreeding. Exponential- (exponential growth occurs in the absence of limiting factors. ) Growth rate= (population at end- population at beginning) Logistic: carrying capacity- population size of the species that the environment can sustain in the long term, given the food, habitat, water and other necessities available in the environment. Type i: k-selected - low density, late maturation, fewer & larger young, longer life spans, more parental care, intense competition for resources. Type iii: r-selected -high density, early maturation, numerous & smaller young, shorter life spans, less parental care, little competition for resources.
