Test 1 Cell Physiology

Natural selection

The increase in frequency of genes that produce phenotypes that raise the likelihood that
animals will survive and reproduce

Adaptation

A physiological mechanism or other trait that is a product of evolution by natural selection.

Adaptive Significance

The reason why the trait is an asset; the reason why natural selection favored the evolution of the trait.

Conformity

The animal allows a specific internal physiological factor—such as body temperature or solute concentration—to match the changing levels of the external environment. (can be dangerous to cells and lead to death if external conditions are extreme)

Regulation

If the animal maintains internal constancy in the face of external variability (this costs a lot of energy to maintain)

Homeostasis

The coordinated physiological processes that maintain most of the constant states in the organism.

Acute Changes

within minutes to hours after exposure; can be reversible

Chronic Changes

within days, weeks or months after exposure; can be reversible; acclimation (lab) and
acclimatization (wild)

Evolutionary Changes

changes that occur by alteration of gene frequencies over the course of many generations (after exposure)

Developmental Changes

changes in physiology of individuals that occur in a programmed way

Changes Controlled by Clocks

changes in physiology that occur with the animals’ internal clocks

Scaling

The length of gestation is a regular function of body size.

Temperature

a measure of the intensity of the random motions that the atoms and molecules in the material
undergo.

Oxygen

Consequence of an animal’s need for metabolic energy. Low solubility in water

Hypoxia

A condition where oxygen is reduced below normal partial pressures (can occur in air and water)

Water

Universal solvent in biological systems.

Evolution

A change of gene frequencies over time in a population of organisms. Some processes are adaptive, and others are not.

Adaptation

When a trait has come to be present at high frequency in a population because it confers a greater probability of survival and successful reproduction in the prevailing environment than available alternative traits. Products of the process of natural selection.

Nonadaptive evolution

because of chance, an allele that provides a lower probability of survival and reproduction than an available alternative comes to be the predominant allele in the population

Genetic Drift

Processes in which chance assumes a preeminent role in altering gene frequencies

Pleiotropy

The genetic phenomenon in which a single gene influences two or more distinct, and seemingly unrelated, phenotypic traits.

Comparative method

seeks to identify adaptive traits by comparing how a particular function is carried out by
related and unrelated species in similar and dissimilar environments.