Question

Daphnia from lakes with large fish predator populations show which of the following?

1) A large degree of phenotypic plasticity for negative phototaxis in the presence or absence of fish-occupied water
2) No phenotypic plasticity relating to phototaxis in the presence or absence of fish-occupied water
3) Extremely strong inducible positive phototaxis in the presence of fish-occupied water
4) Minimal phototaxis in the presence or absence of fish-occupied water

Answer 1

Daphnia exhibit a high degree of phenotypic plasticity for negative phototaxis when detecting the presence of fish predators, which helps them to survive in environments with large predator populations.

Step-by-step explanation:

Daphnia from lakes with large fish predator populations show a large degree of phenotypic plasticity for negative phototaxis in the presence or absence of fish-occupied water. This indicates that when Daphnia detect chemical cues from predators, they exhibit an adaptive behavior to swim away from light sources where predators may be more likely to see and catch them. Phenotypic plasticity allows these organisms to alter their behavior rapidly in response to environmental changes, such as the presence of predators, which can significantly improve their survival chances. Phenotypic plasticity is a critical factor in how species interact within ecosystems and can influence food webs, including the impact on photosynthetic organisms and energy flow within the lake.