Answer: Their broader physiological tolerance to temperature or salinity variation lets them survive in more variable habitats.
- A They generally have higher reproductive rates regardless of the surrounding environmental conditions according to standard textbooks
- B Their broader physiological tolerance to temperature or salinity variation lets them survive in more variable habitats
- C They usually outcompete stenothermal organisms even within stable, unvarying environments in general practice as commonly described
- D Tolerance range has essentially no real relationship to an organism's geographic distribution in most textbook accounts
Correct answer: B. Their broader physiological tolerance to temperature or salinity variation lets them survive in more variable habitats
Explanation: Eurythermal and euryhaline organisms can physiologically tolerate a wide range of temperature or salinity respectively, allowing them to survive and establish populations across more variable and geographically extensive habitats than stenothermal or stenohaline species restricted to narrow tolerance ranges.
Exponential growth produces an ever-steepening J-curve with no limit, an unrealistic long-term model; logistic growth produces an S-curve that levels off at the carrying capacity K, as growth rate (K−N)/K shrinks to zero once resources are fully used.
Concept context
How organisms interact with abiotic factors and respond to stress, plus population attributes, growth models, and interspecific interactions such as predation, competition, and mutualism.