The greatest diversity (number of different species) of organisms can be found in?
C. insects
Would all of the insects in a forest be considered a population? Why, or why not?
I agree with Hana - 'population' usually refers to a single species.
How many insects in the world?
There are actually around 1.2 million described species, and current estimates say that about another 5-30 million species are left to be named. To give you a little perspective about numbers, if you took a giant scale and put all the people on earth on one side and all the ants on the other, the ants would probably outweigh the people, and that's just ants... Again, current estimates say that insects outnumber humans 1-2 billion to 1, so that's about 12 billion billion, probably a conservative estimate at that....
What would happen if all insects were removed from the food chain?
Try the end of terrestrial life on earth as we know it.Without insects, all insectivores die… as do the animals that eat those animals, and vice versa. That's not a serious issue, however. The problem isn't the insects on the bottom of the food chain, but those at the very top… the detritivores. The insects that eat corpses and dung and rotting plant matter. Without these, waste piles up worldwide, water gets polluted, and diseases spread. Furthermore, without these detritivores to return nutrients from wastes to the soil, plus ants and termites and other soil critters to turn and aerate the ground, the soil loses its quality. Plants cannot grow, though that wouldn't matter much for the plants that are pollinated by insects which would die out in a generation, along with the animals that eat them, and the animals that eat those animals, etc. It would be a miserable world for humans: our civilization evolved in a world with Insects, and cannot exist without them.Would all life on earth perish? No. Loss of insects (even in the strictest sense of hexapods only) would be devastating on land, but in the oceans it wouldn't be a problem. Life existed on earth before the insects came ashore, but it was almost entirely aquatic life and a few wind-pollinated plants. Of course, if you count spiders as "insecty," then you'll have to include crabs and isopods and other arthropods. Alas, their role underwater is similar to above, so now you've destabilized the ocean ecosystem too. Get to know the insect world: they're mostly harmless, mostly beneficial, and can be pretty, cute, or even charming once you observe them up close.
How many insects are there in the world?
In an article called "How Many Insects Are There?" in Systematic Zoology from 1953, Curtis W Sabrosky talks about how impossible answering that question is. "No one dares to guess the answer for the world" because we can't even answer that question for a single square mile, as we can only approximate those with square foot measurements [why Sabrosky didn't use metric units I do not know]. The insect population in a given area also varies with season, and even time of day. Swarms and sudden bursts of individuals, like mass hatchings of mayflies, change the populations. Then there's reproduction. Do you count every egg a housefly lays as an individual, or every maggot, or only the adults? Here are some estimates for certain areas: In the top 9-12 inches of grassland soil in England (an area of very low insect diversity compared to, say, the Amazon), the estimates for arthropods (including mites and springtails) are up to several hundred million individuals per acre, and 1/3 to 1/10 of that are insects proper.In the top 5 inches for forest soils in North Carolina, 124 million arthropods estimated in one acre, 4.5 million are insects. In 3 inches of leaf litter and humus in a Pennsylvania forest sample, 9759 arthropods per square foot, figuring to 425 million arthropods per acre, of which 294 million are mites, 119 million springtails, 11 million all other arthropods.A single ant colony in Jamaica had 630000 individuals. Single colonies in Europe have 150000-200000 ants. One study in Maryland found 73 colonies in 10 acres, each with tens to hundreds of thousands of individuals, with an estimate of 27 ants per square foot. Single termite mounds in Australia had 750k, 1806k, and even 3 million termites.Ultimately Sabrosky doesn't give an answer. But if we have, let's say, 10 million individal insects per acre of land, and earth's surface area of land is 36.48 billion acres, that's 364,800,000,000,000,000 insects in the world. If we estimate about a hundred million insects per acre, we're now looking at numbers in the quintillions. Plus, while insects may be the most diverse organisms on earth and are most of earth's biomass, they are actually not the most numerous! Tiny mites outnumber the insects ten fold, as do springtails. Then there's the bacteria, which are in the 10^30 order at least. Short answer: Somewhere between a few million billions and a few trillion millions, or more. Welcome to their world.
Should humans just leave the rainforests alone?
If you want to stay out of the jungle, don't go there. Rainforest is another word for "jungle." Jungle means "hot miserable place."