Why plants are kept in the dark for a week are still able to conduct cellular respiration.?

Of your good in bio kusing a series of preliminary observations; pstate a problem developed from these observations, formulate a hypothesis, design an experiment to test the hypothesis

Which would be the most useful source of evidence to support mcneill's contention?

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?