Ectothermy, Endothermy, and Water Relations

These flashcards encompass key concepts regarding ectothermy, endothermy, and water relations as discussed in the lecture.

Ectothermy

A type of thermoregulation where an organism relies on external environmental heat sources.

Endothermy

The ability of an organism to maintain a stable internal body temperature through metabolic processes.

Homeothermy

The ability to maintain a constant body temperature regardless of external conditions.

Metabolic Rate

The rate at which an organism consumes energy; it can vary with temperature, activity level, and metabolic state.

Thermal Neutral Zone

The range of ambient temperatures where an endothermic organism does not need to expend energy to maintain its body temperature.

Lower Critical Temperature

The ambient temperature at which an endotherm must increase metabolic heat production to maintain body temperature.

Upper Critical Temperature

The ambient temperature at which an endotherm must increase metabolic activity to prevent overheating.

Torpor

A state of decreased physiological activity characterized by reduced metabolism, body temperature, and energy expenditure.

Hibernation

A prolonged state of torpor that occurs in cold months, allowing animals to conserve energy when food is scarce.

Turgor Pressure

The pressure exerted by water inside the cell against the cell wall, maintaining plant structure and function.

Osmoregulation

The process by which organisms regulate the water and solute concentrations within their bodies to maintain homeostasis.

ISO Osmotic

Having the same osmotic pressure as another solution, which prevents the net movement of water across cell membranes.

Hyperosmotic

Describing a solution with a higher concentration of solutes compared to the cell's cytoplasm.

Hypoosmotic

Describing a solution with a lower concentration of solutes compared to the cell's cytoplasm.

Evapotranspiration

The process by which water evaporates from soil and transpiration occurs from plants to the atmosphere.

Relative Humidity

The amount of moisture in the air compared to the maximum amount of moisture the air can hold at that temperature.

Desiccation Tolerance

The ability of organisms to withstand considerable loss of water without dying.

Anhydrobiosis

A state of dormancy that allows an organism to survive extreme dehydration.

Microhabitats

Small, specific habitats that provide conditions suitable for a particular organism, often differing from the larger surrounding habitat.

Piloerection

The raising of hair or feathers to increase insulation in response to cold temperatures.

Thermal Neutrality

The condition under which an organism does not require additional energy to maintain its body temperature.

Kangaroo Rat

A desert-dwelling rodent that survives primarily on metabolic water produced from food and is highly adapted to conserve water.

Trehalose Sugars

Sugars that help certain organisms withstand desiccation by forming protective glassy coatings in their cells.

Scholander Curve

A graph that represents the relationship between metabolic rate and environmental temperature for endothermic organisms.

Glycerol

A compound that can act as an antifreeze, preventing ice formation within cells of organisms exposed to freezing temperatures.