Question

Which of the following is not a characteristic of a stable biological community?

• A. It must be resistant to invasions by alien species.
• B. It should not show too much variation in productivity year to year.
• C. All species are equally important and the absence of any one leads to unsustainability.
• D. It is resilient to occasional disturbances, natural or man-made.
• A. Key species
• B. Endemic species
• C. Community
• D. Species
• A. Paul Ehrlich
• B. David Tilman
• C. Robert May
• D. Edward Wilson
• A. Reptiles
• B. Fishes
• C. Insects
• D. Mammals
• A. Temperate regions are subjected to glaciations, but tropical latitudes remained relatively undisturbed.
• B. Tropical environments have more humidity/moisture which helps diversity flourish.
• C. Tropical environments are less seasonal and more constant.
• D. There is more solar energy available in the tropics which contributes to higher productivity and biodiversity.

Answer 1

The Correct Option is C

(1) It must be resistant to invasions by alien species.

This statement is correct. A stable biological community is typically resistant to invasions by alien species. Resistance to invasions is a characteristic of a stable and mature ecosystem.

(2) It should not show too much variation in productivity from year to year.

This statement is correct. A stable biological community tends to have relatively consistent productivity over time, with minimal variation from year to year. This consistency is indicative of a stable ecosystem.

(3) All the species are equally important in a stable community and the absence of any one leads to its unsustainability.

This statement is incorrect. In a stable biological community, not all species are equally important. Some species, known as keystone species, play a critical role in maintaining the structure and function of the community. The absence of a keystone species can have a significant impact, but the absence of other species may not necessarily lead to the community's unsustainability. The importance of species can vary, and some species may be more redundant or less critical to the overall stability of the community.

(4) It is resilient to occasional disturbances, whether natural or man-made.

This statement is correct. A stable biological community is resilient to occasional disturbances. Resilience is the ability of an ecosystem to recover from disturbances and maintain its structure and function.

Conclusion

The incorrect statement is (3) All the species are equally important in a stable community and the absence of any one leads to its unsustainability.

Answer 2

(1) Key species

This statement is incorrect. While the Rivet Popper Hypothesis does highlight the importance of key species, the "rivet" in the analogy represents any species within the ecosystem, not just key species.

(2) Endemic species

This statement is incorrect. The "rivet" in the Rivet Popper Hypothesis represents any species within the ecosystem, not specifically endemic species.

(3) Community

This statement is incorrect. The "rivet" in the Rivet Popper Hypothesis represents individual species, not the community as a whole.

(4) Species

This statement is correct. In the Rivet Popper Hypothesis, the "rivet" signifies any species within the ecosystem. The hypothesis, proposed by Paul Ehrlich, compares an ecosystem to an airplane where each species is like a rivet holding the plane together. Removing a rivet (losing a species) may not immediately affect the plane's (ecosystem's) stability, but as more rivets are removed, the plane becomes weaker, illustrating the cumulative impact of species loss on ecosystem stability.

Conclusion

The correct answer is (4) Species. The "rivet" in the Rivet Popper Hypothesis signifies any species within the ecosystem.

Answer 3

(1) Paul Ehrlich

Paul Ehrlich is known for his work on population biology and the concept of the "rivet popper hypothesis," but he did not prove the direct correlation between species richness and community stability.

(2) David Tilman

David Tilman conducted long-term ecosystem experiments that demonstrated a direct correlation between species richness and the stability of a community. His research showed that plots with more species had less year-to-year variation in total biomass, indicating greater stability.

(3) Robert May

Robert May is known for his theoretical work on the stability and complexity of ecosystems, but he did not directly prove the correlation between species richness and community stability through experimental research.

(4) Edward Wilson

Edward Wilson is renowned for his work on biodiversity and sociobiology, but he did not conduct experiments to prove the direct correlation between species richness and community stability.

Conclusion

The correct answer is (2) David Tilman, as his research provided empirical evidence that species richness directly correlates with the stability of a community.

Answer 4

(1) Reptiles

Reptiles are a diverse group, but they are not the most species-rich among vertebrates. There are approximately 10,000 to 12,000 species of reptiles.

(2) Fishes

Fishes are the most species-rich group among vertebrates. There are estimated to be around 34,000 species of fish, which is more than the combined total of all other vertebrate species.

(3) Insects

Insects are not vertebrates; they belong to the invertebrate group. Therefore, this option is not relevant to the question about vertebrates.

(4) Mammals

Mammals are a significant group of vertebrates, but they are not the most species-rich. There are approximately 5,500 species of mammals.

Conclusion

The correct answer is (2) Fishes, as they are the most species-rich group among vertebrates.

Answer 5

(1) Temperate regions are subjected to glaciations, but tropical latitudes have remained relatively undisturbed.

This statement is correct. One hypothesis for the greater biodiversity in the tropics is that temperate regions have experienced glaciations, which can disrupt and reduce biodiversity. In contrast, tropical regions have remained relatively undisturbed, allowing biodiversity to flourish.

(2) Tropical environments have more humidity/moisture which helps the diversity to flourish.

This statement is incorrect. While tropical environments do have more humidity and moisture, which can support high biodiversity, this statement is not a hypothesis explaining the greatest biological diversity in the tropics. Instead, it describes a condition that supports biodiversity.

(3) Tropical environments are less seasonal and more constant.

This statement is correct. One hypothesis for the greater biodiversity in the tropics is that tropical environments are less seasonal and more constant, providing a stable environment for species to thrive.

(4) There is more solar energy available in the tropics which contributes to higher productivity and hence, biodiversity.

This statement is correct. One hypothesis for the greater biodiversity in the tropics is that the higher availability of solar energy leads to higher productivity, which in turn supports a greater variety of species.

Conclusion

The incorrect statement is (2) Tropical environments have more humidity/moisture which helps the diversity to flourish. This statement describes a condition rather than a hypothesis explaining the greatest biological diversity in the tropics.