Ecology Of Individual Organisms 3 — Questions and Answers
Question 1: Which behavioral strategy describes an animal actively seeking out warmer microhabitats to raise its body temperature?
- Countercurrent exchange
- Behavioral thermoregulation (Correct answer)
- Metabolic acclimatization
- Torpor induction
Correct answer: Behavioral thermoregulation
Behavioral thermoregulation involves using movement and habitat selection—such as basking—to regulate body temperature without internal heat production.
Question 2: What does the term 'acclimation' specifically describe in individual organism ecology?
- Evolutionary adaptation over many generations
- Short-term physiological adjustments to environmental change within an individual's lifetime (Correct answer)
- Migration to a new geographic region
- Genetic mutation triggered by environmental stress
Correct answer: Short-term physiological adjustments to environmental change within an individual's lifetime
Acclimation refers to reversible, short-term physiological changes in an individual in response to environmental variation, not genetic evolution.
Question 3: An organism found only within a narrow range of salinity is described as:
- Euryhaline
- Stenohaline (Correct answer)
- Osmoconformer
- Halophyte
Correct answer: Stenohaline
Stenohaline organisms can tolerate only a narrow salinity range, making them sensitive to changes in aquatic salt concentrations.
Question 4: Which structural adaptation in the nasal passages of some desert mammals reduces respiratory water loss?
- Enlarged turbinate bones that cool exhaled air (Correct answer)
- Reduced nostril diameter to limit airflow
- Mucus secretion that traps inhaled moisture
- Countercurrent capillary networks in the trachea
Correct answer: Enlarged turbinate bones that cool exhaled air
Turbinate bones create a large surface area that warms and humidifies inhaled air but cools exhaled air, recapturing moisture before it is lost.
Question 5: In ecology, 'fitness' at the individual organism level is most precisely defined as:
- Physical strength and endurance of an organism
- An individual's ability to avoid predation
- The relative contribution of an individual's genes to the next generation (Correct answer)
- Metabolic efficiency of energy use
Correct answer: The relative contribution of an individual's genes to the next generation
Ecological fitness measures reproductive success—specifically how many offspring an individual contributes to the next generation relative to others.
Question 6: Why do some intertidal organisms produce heat-shock proteins during exposure to air at low tide?
- To attract prey during thermal stress
- To stabilize and repair proteins damaged by high temperature or desiccation (Correct answer)
- To signal territory to competitors
- To speed up metabolic reactions during warm periods
Correct answer: To stabilize and repair proteins damaged by high temperature or desiccation
Heat-shock proteins act as molecular chaperones that refold denatured proteins and prevent aggregation during thermal and desiccation stress.
Question 7: Which of the following is an example of a semelparity reproductive strategy?
- A songbird that raises two broods per summer for several years
- A Pacific salmon that reproduces once and then dies (Correct answer)
- A sea turtle that lays eggs on the same beach every three years
- A deer that produces one fawn each spring throughout its life
Correct answer: A Pacific salmon that reproduces once and then dies
Semelparous organisms invest all reproductive effort into a single breeding event, after which they typically die, as seen in Pacific salmon.
Ecology Of Individual Organisms 3
Which behavioral strategy describes an animal actively seeking out warmer microhabitats to raise its body temperature?