Answer and Explanation:
Observing population directly gives you accurate result .
Direct observation does not need any intermediary as they themselves go for survey.
So, it is cost efficient.
Whereas indirect observing may involve manipulations.
It requires someone or many to hire who helps in surveying.
It incurs cost.
Thus, direct observation is always better than indirect observation.
Answer: I believe this is FALSE.
Explanation: I say this because, although photosynthesis is required to keep the plants alive which causes respiration. It is not objectively needed in the cycle, and it isn't caused by animals.
I hope this helps :D.
Answer:
Burning fossil fuels like coal and oil puts more carbon dioxide into our atmosphere. NASA has observed increases in the amount of carbon dioxide and some other greenhouse gases in our atmosphere. Too much of these greenhouse gases can cause Earth's atmosphere to trap more and more heat. This causes Earth to warm up.
Answer:
Fishing down the food web is the process whereby fisheries in a given ecosystem, "having depleted the large predatory fish on top of the food web, turn to increasingly smaller species, finally ending up with previously spurned small fish and invertebrates".