Although the actual questions are missing from your ask, here's how you can tell.
If the study will be messed up (added bias) through interaction with the subjects the study should be observational. For example if a biologists wanted to study the eating habits of wild birds in the tropics, they would need to do an observational study. if they did a controlled experiment, the birds will change their eating habits based on human interaction, thus making the study invalid.
If the study requires specific measurements, close monitoring, or contact and interaction with the subjects the study should be a controlled experiment. For example, if a scientist wanted to test out a new drug, the health of patients would need to be closely monitored.
Explanation:
wings on butterflies, bats, and birds.
Answer:
As we know 10% law is transfer of energy from higher trophic level to lower trophic level. So as the energy are transfer from one organism to another there is a loss of energy as that energy are utilised by the oragnism and only 10% of the total energy is transferred to the second consumer.
Explanation:
Quetinary consumer are at the higher position in the food chain so they do not get enough energy from prey they have to feed on several organism for the enegy. And also they are at the top of the food chain so they are not eaten by other animal, their life span are also more than primary consumer.
In other hand primary consumer get enough energy but they are prey for other higher tropic level.
Primary and secondary consumer are maintend in such a way by the nature thats make a ecological balance of the habitant.
