(2) BIS2B Final

Species richness

Total number of species present.

Species evenness

Abundance of each species.

Windward

Refers to the side of a mountain that receives more moisture and precipitation.

Leeward

The side of a mountain that is drier and receives less moisture.

Semelparous

Organisms that reproduce once and then die.

Iteroparous

Organisms that reproduce many times during their lifetime.

r selected species

Species characterized by small body size, short life expectancy, rapid growth, early reproduction, and producing many small offspring.

K selected species

Species characterized by large body size, long life expectancy, slow growth, and producing few large offspring.

Ectotherm

Organisms whose body temperature is primarily controlled by external conditions.

Endotherm

Organisms whose body temperature is primarily controlled by metabolic processes.

Bergmann’s Rule

Body size should be correlated with habitat temperature.

Allen’s Rule

Length of limbs should be correlated with habitat temperature.

Fundamental niche

The abiotic conditions in which a species can survive and reproduce.

Realized niche

Biotic conditions in which a species can survive and reproduce, determined by species interactions.

Autotrophs

Organisms that are self-feeding.

Heterotrophs

Organisms that feed on others, such as herbivores and carnivores.

C3 pathway

A photosynthetic pathway common in most plants involving the fixation of CO₂ into a 3-carbon compound.

C4 pathway

A photosynthetic pathway common in plants of hot, sunny environments that minimizes photorespiration.

CAM pathway

A photosynthetic pathway that fixes CO₂ at night, common in succulents and desert plants.

Principle of allocation

Organisms have a limited amount of resources for life functions, leading to tradeoffs in resource allocation.

Liebig’s Law of Minimum

Plant growth is determined by the resource that is most scarce relative to plant needs.

Optimal foraging theory

Theory that maximizes the energy benefit to cost ratio of feeding decisions.

Hypertonic solution

A solution that causes a cell to shrivel due to loss of water.

Isotonic solution

A solution that results in a normal cell size.

Hypotonic solution

A solution that causes a cell to swell due to water gain.

Acclimation

A short-term, reversible behavioral response to environmental changes.

Adaptation

A long-term, irreversible behavioral response to environmental changes.

Density independent controls

Factors affecting population size that do not depend on population size, usually abiotic.

Density dependent controls

Factors affecting population size that dependent on population size, usually biotic.

Logistic growth equation

Nt = K/1+{(K-N0)/N0] e^-rt, used to model population growth.

Catastrophism

The idea that Earth and life are shaped by major, sudden events.

Gradualism

The idea that Earth and life are shaped by long, slow processes.

Heritability

A measure of how much variation in a trait is due to genetic factors.

Relative fitness

The average contribution to the gene pool of the next generation made by a specific genotype.

Breeder’s equation

R = h^2S, representing response to selection.

Positive frequency dependent selection

Common phenotypes have the highest fitness.

Negative frequency dependent selection

Rarer phenotypes have the highest fitness.

Mycorrhizae

Symbiotic relationship between fungi and plants, typically non-leguminous.

Rhizobia

Bacteria that partner with legumes, forming nodules for nitrogen fixation.