Textbook - Chapter 7: Animal Adaptations Flashcards
Biological clock
The internal mechanism of an organism that controls circadian rhythms iwhtout external time cues
Critical temperature
Range of ambient temperature outside the thermoneutral zone in which metabolic rate increases with changes in temperature
Critical day length
The period of daylight, specific for any given species that triggers a long-day or a short-day response in organisms
Countercurrent heat exchange
An anatomical and physiological arrangement by which heat exchanges takes place between outgoing warm arterial blood and cool venous blood returning to the body core; important in maintaining temperature homeostasis in many vertebrates
Carnivore
Organism that feeds on animal tissue; taxonomically, a member of the order Carnivora (Mammalia)
Circadian rhythm
Endogenous rhythm of physiological or behaioral activity of approximately 24 hours duration
Convection
Transfer of ehat by the circulation of a liquid or gas
Conductivity
Ability to exchange heat with the surrounding environment
Diapause
A period of dormancy, usually seasonal, in the life cycle of an insect, in which growth and development cease and metabolism greatly decreases
Day neutral plant
A plant that does not require any particular photoperiod to flower
Detrivore
Organism that feeds on dead organic matter; usually applies to detrius-feding organisms other tahn bacteria and fungi
Endothermy
Regulation of body temperature by internal heat production; allows maintenance of appreciable difference between body temperature and external temperature
Ectothermy
Determination of body temperature primarily by external thermal conditions
Fermentation
Breakdown of carbohydrates and other organic matter under anaerobic conditions
Hypoosmotic
Having a lower concentration of salts in the body tissue than does the surrounding water
Hyperosmotic
Having a higher concentration of salts in the body tissue than does the surrounding water
Homeothermy
Regulation of body temperature by physiological means
Homeotherm
Animal with a fairly constant body temperature; also spelled homoiotherm and homotherm
Homeostatic plateau
Limited range of maximum and minimum values of physiological tolerances within which an organism operates
Homeostasis
Maintenance of a nearly constant internal environment in the midst of a varying external environment; more generally, the tendency of a biological system to maintain itself in a state of stable equilibrium
Hibernation
Winter dormancy in animals, characterized by a great decrease in metabolism
Heterotherm
An organism that during part of its life history becomes either endothermic or ectothermic; hibernating endotherms become ectothermic; and foraging insects such as bees become endothermic during periods of activity; they are characterized by rapid, drastic, repeated changes in body temperature
Herbivore
Organism that feeds on plant tissue
Isosmotic
A characteristic describing an organism with body fluids that have the same osmotic pressure as seawater
Long-day organism
Plant or animal that requires long days, days with more than a certain minimum of daylight to flower or come into reproductive condition
Omnivore
An animal (heterotroph) that feeds on both plant and animal matter
Operative temperature range
Range of body temperatures at which poikilotherms carry out daily activity
Poikilotherm
An organism whose body temperature varies according to the temperature of its surrounding
Poikilothermy
Variation of body temperature with external conditions
Rete
A large network or discrete vascular bundle of intermingling small blood vessels carrying arterial and venous blood that acts as a heat exchanger in mammals and certain fish and sharks
Scaling
The process by which most morphological and physiological features change as a function of body size in a predictable way
Short-day organisms
Plants and animals that come into reproductive codition under conditions of short days, days with less than a certain maximum length
Supercooling
In ectotherms, lowering body temperature below freezing without freezing body tissue, by means of solutes
Torpor
Temporary great reduction in an animal’s respiration, with loss of moton and feeling; reduces energy expenditure in response to some unfavorable environmental condition, such as heat or cold
Thermoneutral Zone
Range of environmental temperatures within which the metabolic rates are minimal
Thermal conductivity
Ability to conduct or transmit heat