Which one of the following has the largest population in a food chain

It's a Fish-Eat-Fish World Some 300,000 marine species are known to science—about 15 percent of all the species identified on the planet. But the sea is so vast that a million or more as yet unknown species may live in its waters. Most of these aquatic species are tied together through the food web. Level One: Photo autotrophs The foundation of the sea's food chain is largely invisible. Countless billions of one-celled organisms, called phytoplankton, saturate sunlit upper-ocean waters worldwide. These tiny plants and bacteria capture the sun's energy and, through photosynthesis, convert nutrients and carbon dioxide into organic compounds. On the coast, seaweed and seagrasses do the same thing. Together, these humble plants play a large role: They are the primary producers of the organic carbon that all animals in the ocean food web need to survive. They also produce more than half of the oxygen that we breathe on Earth. Level Two: Herbivores The next level of the marine food chain is made up of animals that feast on the sea's abundant plant life. On the ocean's surface waters, microscopic animals— zooplankton, which include jellyfish and the larval stages of some fish, barnacles, and mollusks—drift across the sea, grazing opportunistically. Larger herbivores include surgeonfish, parrotfish, green turtles, and manatees. Despite their differences in size, herbivores share a voracious appetite for ocean vegetation. Many of them also share the same fate—which is to become foo...

Living creatures that eat organisms from a different population A consumer in a Consumers are typically viewed as predatory animals such as meat-eaters. However, herbivorous animals and parasitic fungi are also consumers. To be a consumer, an organism does not necessarily need to be carnivorous; it could only eat plants (producers), in which case it would be located in the first level of the food chain above the producers. Some carnivorous plants, like the consume which means to eat. Levels of the food chain [ ] Within an ecological food chain, consumers are categorized into primary consumers, secondary consumers, and tertiary consumers. • Primary consumers are • Secondary consumers are • Tertiary consumers, which are sometimes also known as Importance to the ecosystem [ ] In an ecosystem, energy is transferred from level to another as food. A balance in these transfers is vital to the health and stability of an ecosystem. See also [ ] • • • References [ ]

Organisms of different species can interact in many ways. They can compete, or they can be symbionts (long-term partners with a close association). Or, of course, they can do what we so often see in nature programs: one of them can eat the other. (Chomp!) That is, they can form one of the links in a food chain. In ecology, a food chain is a series of organisms that eat one another (so that energy and nutrients flow from one to the next). For example, if you had a hamburger for lunch, you might be part of a food chain that looks like: grass → \rightarrow → right arrow cow → \rightarrow → right arrow human. But what if you had lettuce on your hamburger? In that case, you're also part of a food chain that looks like: lettuce → \rightarrow → right arrow human. As this example illustrates, we can't always fully describe what an organism (such as a human) eats with one linear pathway. For situations like that, we may want to use a food web, which consists of many intersecting food chains and represents the different things an organism can eat, and be eaten by. Autotrophs are the foundation of every ecosystem on the planet. That may sound dramatic, but it's no exaggeration! Autotrophs form the base of food chains and food webs, and the energy they capture from light or chemicals sustains all the other organisms in the community. When we're talking about their role in food chains, we can call autotrophs producers. Heterotrophs (“other-feeders”) such as humans can't capture light o...