The correct answer is - 1) inverted pyramid, with a narrow base representing a small number of young individuals.
The populations that are decreasing are usually population in countries that are highly developed. The conditions for living are excellent, the medical care on high level, life expectancy very high, but the birth rates very low.
In this type of conditions, there's smaller and smaller number of young individuals, with the middle aged population being much bigger, and the older population being constantly on the rise. This will give the age-structure histogram a reverse shape than what it is supposed to have, it will be similar in appearance like a inverted pyramid, meaning that the population is aging and that it will be constantly on a decline in the future.
By multiplying the rate constant by the substrate concentration (amount) or by determining reaction velocity (V).
Answer - B
Reason - Since the area is in the tropics there will be time to time heavy precipitation, which over time the decomposed nutrients will get washed down into a run off and depleted.
In oxidation, oxygen is needed to create a chemical reaction.
