Organisms and Populations

Temperature, Water availability, Light intensity, Soil composition

Temperature, water, light, and soil are the four major abiotic (non-living) factors that influence organisms. Predation and competition are biotic (living) factors.

Mutualism

In mutualism, both species benefit from the interaction (+ +). Competition harms both (- -), predation benefits predator but harms prey (+ -), and parasitism benefits parasite but harms host (+ -).

K

K represents the carrying capacity - the maximum population size that an environment can sustain. N represents population size, r represents growth rate, and B represents births.

Spines

In desert plants like Opuntia (prickly pear), leaves are modified into spines to reduce water loss through transpiration. The flattened stem takes over the photosynthetic function.