As the number of species in a food web increases

Correct option is A

Introduction
· A food web is a graphical representation of the complex interconnecting feeding relationships within an ecological community, consisting of multiple overlapping food chains.
· The structure of a food web is defined by its richness (number of species) and connectance (the actual number of links relative to the potential links).
· As ecosystems become more complex, the pathways through which energy and nutrients travel diversify, influencing the overall architecture of the biological community.

Information Booster
· The correct answer is Food chain length tends to increase, as a higher number of species (species richness) provides more potential nodes for energy transfer, allowing for longer vertical pathways.
· In a complex food web, the addition of new species often fills intermediate trophic levels or adds top predators, which mathematically and biologically extends the average and maximum length of food chains.
· Ecological studies have shown a positive correlation between ecosystem size/biodiversity and the number of trophic levels that the system can support.
· Greater species diversity allows for "trophic omnivory" and complex interactions that sustain longer sequences of "who eats whom" compared to simple, species-poor systems.
· This expansion is often limited by the thermodynamic efficiency of energy transfer, but a larger species pool provides the structural basis for these longer chains to exist.

Additional Knowledge
· System tends to be unstable is a statement often debated in ecology; while early models by Robert May suggested large systems could be unstable, modern ecological theory suggests that complexity (high species number) actually promotes "functional redundancy" and stability.
· Energy flow decreases is incorrect because an increase in species, especially at the producer level, typically indicates a more efficient utilization of available resources, potentially increasing the total energy throughput of the system.
· System tends to collapse completely is incorrect because increased biodiversity acts as an insurance policy for the ecosystem; if one species fails, others are available to fill its functional role, preventing a total collapse.
· The length of a food chain is ultimately governed by the "Energy Efficiency Hypothesis," which states that since only about 10% of energy is transferred between levels, there is a physical limit to how many species can be stacked vertically.