← Back to 1. Evolution and the theme of Biology and Scientific Inquiry

📝 Impact of global warming on organisms and biodiversity (12 MCQs)

📖 From Campbell Biology • 1. Evolution and the theme of Biology and Scientific Inquiry • 12 questions available

←Previous Topic:Climate change effects on ecosystems📝 Impact of global warming on organisms and biodiversityHow Evolution Explains Unity and Diversity of Life:Next Topic→

What is Impact of global warming on organisms and biodiversity?

Definition:
The impact of global warming on organisms and biodiversity refers to the adverse effects of rising global temperatures on individual species and the variety of life on Earth, including shifts in geographic ranges, changes in life cycle events (phenology), reduced fitness, increased extinction risks, and disruptions in ecological interactions, which collectively erode genetic, species, and ecosystem diversity.

Working:
Global warming works by altering thermal environments beyond the optimal ranges for many species, where the performance of an organism can be modeled by a thermal performance curve, often described by the equation $\text{Performance} = \text{Maximum} \times e^{-0.5 \left(\frac{T-T_{opt}}{T_{width}}\right)^2}$ , and species with limited ability to adapt or migrate face population declines, while invasive species may thrive, leading to community composition changes and loss of biodiversity.

Example:
A simple example is the polar bear, which relies on sea ice to hunt seals, but with global warming reducing ice cover, polar bears have less access to prey, leading to starvation, reduced reproduction, and population decline, and this effect is compounded by reduced genetic diversity as populations become isolated, illustrating the direct and indirect impacts of warming on a keystone species.

Reason:
Understanding the impact of global warming is crucial because biodiversity underpins ecosystem resilience and human well-being, providing food, medicine, and ecosystem services, and its loss threatens our ability to adapt to future changes, making it a priority for conservation biology, climate policy, and sustainable development.

Easy

Medium

Hard

📝 All Impact of global warming on organisms and biodiversity MCQs

Q1. A mountain plant survives only within a narrow temperature range. As average temperature rises, which outcome is most likely if the plant cannot migrate or adapt rapidly?

A.Its population may decline as suitable habitat becomes smaller ✅

B.Its population will increase because warmer temperatures always improve growth

C.Its genetic variation will immediately disappear

D.Its predators will automatically become less abundant

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: A narrow thermal tolerance makes the plant vulnerable when warming pushes conditions beyond its suitable range. If migration and adaptation are limited, survival and reproduction decline, causing population size to decrease over generations.

Q2. Two bird populations occupy similar habitats. Population X migrates seasonally, while population Y does not. Spring temperatures rise earlier over several decades. Why might population X initially cope better?

A.Migration can allow X to track favorable conditions ✅

B.Migration prevents all effects of temperature change

C.Y will necessarily evolve faster because it does not migrate

D.X will have no competition for food

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: Migration can allow organisms to move toward areas where temperature and resources remain suitable. However, migration does not eliminate climate effects, and its success depends on whether suitable habitat remains connected and available.

Q3. A coral reef experiences repeated periods of unusually warm water. After each event, coral growth decreases and mortality increases. Which prediction best describes the long-term ecosystem effect?

A.Reduced coral abundance can simplify habitat and affect many dependent species ✅

B.Only coral populations will change because species interactions are unaffected

C.Fish populations must increase because fewer corals reduce competition

D.The reef will remain unchanged if temperatures eventually return to normal

💡 Difficulty: hard | ✅ Correct: A

📖 Explanation: Corals provide structural habitat for many organisms. Repeated warming can reduce coral abundance, decreasing shelter and resources for associated species. Thus, climate stress can propagate through an ecosystem rather than affecting only one population.

Q4. A student claims, “If a species currently has a large population, climate change cannot threaten it.” Which evidence most directly challenges this reasoning?

A.A large population may still have a narrow environmental tolerance ✅

B.Large populations always have lower genetic diversity

C.Climate change affects only rare species

D.Population size determines the exact temperature tolerance of every individual

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: Population size alone does not determine vulnerability. A large population with specialized habitat requirements or narrow environmental tolerance can decline rapidly when environmental conditions shift beyond the range needed for survival and reproduction.

Q5. A forest loses a tree species after several decades of warming. Herbivorous insects that depended heavily on its leaves also decline. Which interpretation best explains this pattern?

A.Climate change can indirectly affect organisms through changes in resource availability ✅

B.The insects must have been directly killed by increased temperature

C.The tree and insects were unrelated because they occupy different trophic levels

D.The decline proves that all herbivores respond identically to warming

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: Climate change can alter species indirectly by changing food, shelter, or other resources. Loss of a tree species reduces an important resource for dependent herbivores, demonstrating how environmental change can spread through ecological interactions.

Q6. An ecosystem model predicts that warming increases plant productivity at first, but productivity later declines as drought becomes more severe. Which explanation best accounts for this pattern?

A.Temperature initially promotes growth, but increasing water limitation eventually becomes stronger ✅

B.Warming always increases productivity regardless of water availability

C.Drought affects animals but cannot affect plants

D.The decline must mean plants have stopped undergoing photosynthesis entirely

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: Moderate warming can improve growth for organisms operating below their temperature optimum, but continued warming may increase evaporation and water stress. Once drought becomes limiting, reduced water availability can outweigh the initial temperature benefit.

Q7. A graph shows annual insect abundance rising from 2000 to 2010 while average temperature also rises, but insect abundance falls sharply from 2011 to 2020 as warming continues. What conclusion is best supported?

A.The relationship between temperature and abundance may be nonlinear ✅

B.Temperature must have no influence on insects

C.The first decade proves warming permanently benefits insects

D.The decline proves insects cannot tolerate any temperature increase

💡 Difficulty: hard | ✅ Correct: A

📖 Explanation: The graph suggests that warming may produce different effects at different temperatures. Initial increases could occur near a favorable range, while later declines may result when temperatures exceed tolerance limits or interact with drought and resource shortages.

Q8. A conservation team can either protect a species’ current habitat or create connected habitat farther toward a cooler region. The species has low dispersal ability and warming is projected to continue. Which strategy is more likely to provide long-term benefit?

A.Creating connected habitat toward suitable future conditions ✅

B.Protecting only the current habitat indefinitely

C.Removing all competing species from the current habitat

D.Increasing population density without changing habitat conditions

💡 Difficulty: hard | ✅ Correct: A

📖 Explanation: If warming progressively makes the current habitat unsuitable, protection alone may provide only temporary benefits. Connected habitat toward cooler areas can improve movement and allow populations to track shifting environmental conditions.

Q9. Researchers observe that a flowering plant now blooms earlier, while its primary pollinator changes its activity period only slightly. What ecological consequence is most plausible?

A.A timing mismatch could reduce successful pollination ✅

B.Pollination must increase because flowers appear earlier

C.The plant will automatically switch to a different pollinator

D.The pollinator will immediately evolve identical timing

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: Climate change can alter seasonal timing at different rates among interacting species. If flowering advances substantially while pollinator activity changes little, the overlap between plant reproduction and pollinator availability may decrease.

Q10. A scientist compares two lakes. Lake A has many species with overlapping ecological roles, while Lake B has fewer species and more specialized roles. After warming, both lose one sensitive species. Which lake is more likely to maintain ecosystem functioning?

A.Lake A, because overlapping roles may provide functional redundancy ✅

B.Lake B, because fewer species always means greater stability

C.Both must respond identically because one species was lost

D.Lake B, because specialization prevents ecological disruption

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: Species with overlapping ecological roles can provide functional redundancy. If one species declines, another may partially maintain the same ecological process. Therefore, Lake A may be more resilient to the loss of one sensitive species.

Q11. A population contains individuals with different heat tolerances. Over many generations, warming causes heat-sensitive individuals to leave fewer offspring, while heat-tolerant individuals reproduce more successfully. What process could increase heat tolerance in the population?

A.Natural selection acting on heritable variation ✅

B.Acclimation that changes every individual's DNA identically

C.Random extinction with no effect on population traits

D.Competition that guarantees every individual becomes heat tolerant

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: If heat tolerance varies among individuals and some of that variation is heritable, warmer conditions can favor individuals with greater tolerance. Their higher reproductive success can increase the frequency of tolerance-associated traits over generations.

Q12. A marine species can either remain in its current region or move toward cooler waters. Cooler waters have less food, but the current region is approaching the species’ upper thermal limit. Which decision would maximize persistence if food shortage reduces reproduction but extreme heat causes high mortality?

A.Move toward cooler waters if the reduction in mortality outweighs the reproductive cost ✅

B.Remain in the warm region because food availability always matters more than temperature

C.Move only after every individual dies in the original region

D.Remain because migration cannot affect population survival

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: Persistence depends on balancing multiple limiting factors. If extreme heat causes sufficiently high mortality, moving to cooler habitat may produce greater overall survival even when food availability is lower, provided reproduction remains possible.

🔗 Related Topics (MCQs)

📝 The Study of Life Reveals Unifying Themes MCQs 📝 Hierarchical organization of life MCQs 📝 Reductionism in biology MCQs 📝 Emergent properties biology MCQs 📝 Systems biology MCQs

←Previous Topic:Climate change effects on ecosystems📝 Impact of global warming on organisms and biodiversityHow Evolution Explains Unity and Diversity of Life:Next Topic→