<p><img alt="" class="" height="310" src="https://data.ulearngo.com/assets/22864b88-9092-4b3a-8941-5e1162c2df02" width="414"/></p>
<h3><strong>What is happening inside each leaf and blade of grass?</strong></h3>
<p>Photosynthesis. Maybe the most important biochemical <a data-lesson="biochemical-reactions" data-subject="biology" data-tutorial="biology-foundations" href="https://app.ulearngo.com/biology/biology-foundations/biochemical-reactions">reaction</a> of Earth. As sunlight shines down on this forest, the sunlight is being absorbed, and the energy from that sunlight is being transformed into chemical energy. That chemical energy is then distributed to all other living organisms in the ecosystem.</p>
<h2>Flow of Energy</h2>
<p>To survive, ecosystems need a constant influx of energy. Energy enters ecosystems in the form of sunlight or chemical compounds. Some organisms use this energy to make food. Other organisms get energy by <a data-lesson="balanced-eating" data-subject="biology" data-tutorial="human-biology" href="https://app.ulearngo.com/biology/human-biology/balanced-eating">eating</a> the food.</p>
<h3>Producers</h3>
<p><strong>Producers</strong> are organisms that produce <a data-lesson="ingestion" data-subject="biology" data-tutorial="digestive-system" href="https://app.ulearngo.com/biology/digestive-system/ingestion">food</a> for themselves and other organisms. They use energy and simple inorganic <a data-lesson="first-organic-molecules" data-subject="biology" data-tutorial="evolution-overview" href="https://app.ulearngo.com/biology/evolution-overview/first-organic-molecules">molecules</a> to make organic compounds. The stability of producers is vital to ecosystems because all organisms need organic molecules. Producers are also called <strong>autotrophs</strong>. There are two basic types of autotrophs: photoautotrophs and chemoautotrophs.</p>
<ol>
<li><strong>Photoautotrophs</strong> use energy from sunlight to make food by photosynthesis. They include plants, algae, and certain bacteria (see the figure below).</li>
<li><strong>Chemoautotrophs</strong> use energy from chemical <a data-lesson="molecules-for-life" data-subject="biology" data-tutorial="chemistry-of-life-intro" href="https://app.ulearngo.com/biology/chemistry-of-life-intro/molecules-for-life">compounds</a> to make food by chemosynthesis. They include some bacteria and also archaea. Archaea are microorganisms that resemble bacteria.</li>
</ol>
<div class="wp-caption alignnone" style="width: 483px"><img alt="Photoautotrophs include plants, algae, and bacteria and can be found in terrestrial and aquatic ecosystems" height="500" src="https://data.ulearngo.com/assets/cfe6fd2c-cbb9-44b9-8aee-d7dfe497a521" title="Photoautotrophs include plants, algae, and bacteria and can be found in terrestrial and aquatic ecosystems" width="483"/><p class="wp-caption-text">Different types of photoautotrophs are important in different ecosystems.</p></div>
<h3>Consumers</h3>
<p>Consumers are organisms that depend on other organisms for food. They take in <a data-lesson="first-organic-molecules" data-subject="biology" data-tutorial="evolution-overview" href="https://app.ulearngo.com/biology/evolution-overview/first-organic-molecules">organic molecules</a> by essentially “eating” other living things. They include all animals and fungi. (Fungi don't really “eat”; they absorb nutrients from other organisms.) They also include many bacteria and even a few plants, such as the pitcher plant shown in the figure below. Consumers are also called heterotrophs. Heterotrophs are classified by what they eat:</p>
<ul>
<li><strong>Herbivores</strong> consume producers such as plants or algae. They are a necessary link between producers and other consumers. Examples include deer, rabbits, and mice.</li>
<li><strong>Carnivores</strong> consume animals. Examples include lions, polar bears, hawks, frogs, salmon, and spiders. Carnivores that are unable to digest plants and must eat only animals are called obligate carnivores. Other <a data-lesson="herbivores-omnivores-and-carnivores" data-subject="biology" data-tutorial="digestive-system" href="https://app.ulearngo.com/biology/digestive-system/herbivores-omnivores-and-carnivores">carnivores</a> can digest plants but do not commonly eat them.</li>
<li><strong>Omnivores</strong> consume both plants and animals. They include humans, pigs, brown bears, gulls, crows, and some <a data-lesson="summarizing-community-ecology" data-subject="biology" data-tutorial="population-community-ecology" href="https://app.ulearngo.com/biology/population-community-ecology/summarizing-community-ecology">species</a> of fish.</li>
</ul>
<p><img alt="A pitcher plant is different from other plants because it is not a producer, it is a consuemer" src="https://data.ulearngo.com/assets/708ad0cf-f803-4b7e-8721-1ed7bf20f1a8" title="A pitcher plant is different from other plants because it is not a producer, it is a consuemer"/></p>
<p>This image above shows the Pitcher Plant. Virtually all plants are producers. This pitcher plant is an exception. It consumes insects. It traps them in a sticky substance in its “pitcher.” Then it secretes <a data-lesson="enzymes-2" data-subject="biology" data-tutorial="biology-foundations" href="https://app.ulearngo.com/biology/biology-foundations/enzymes-2">enzymes</a> that break down the insects and release nutrients. Which type of consumer is a pitcher plant?</p>
<h3>Decomposers</h3>
<p>When organisms die, they leave behind energy and matter in their remains. <strong>Decomposers</strong> break down the remains and other wastes and release simple inorganic molecules back to the environment. Producers can then use the molecules to make new organic compounds. The stability of decomposers is essential to every ecosystem. Decomposers are classified by the type of organic matter they break down:</p>
<ul>
<li><strong>Scavengers</strong> consume the soft <a data-lesson="complex-tissue-structure" data-subject="biology" data-tutorial="introducing-animal-diversity" href="https://app.ulearngo.com/biology/introducing-animal-diversity/complex-tissue-structure">tissues</a> of dead animals. Examples of scavengers include vultures, raccoons, and blowflies.</li>
<li><strong>Detritivores</strong> consume <strong>detritus</strong>—the dead leaves, animal feces, and other organic debris that collects on the <a data-lesson="summarizing-the-soil" data-subject="biology" data-tutorial="soil-plant-nutrition" href="https://app.ulearngo.com/biology/soil-plant-nutrition/summarizing-the-soil">soil</a> or at the bottom of a body of water. On land, detritivores include earthworms, millipedes, and dung beetles (see the figure below). In water, detritivores include “bottom feeders” such as sea cucumbers and catfish.</li>
<li><strong>Saprotrophs</strong> are the final step in decomposition. They feed on any remaining organic matter that is left after other decomposers do their work. Saprotrophs include <a data-lesson="kingdom-fungi" data-subject="biology" data-tutorial="classification-introduction" href="https://app.ulearngo.com/biology/classification-introduction/kingdom-fungi">fungi</a> and single-celled protozoa. Fungi are the only organisms that can decompose wood.</li>
</ul>
<div class="wp-caption alignnone" style="width: 500px"><img alt="A dung beetle is an example of a detritivore" height="375" src="https://data.ulearngo.com/assets/82a590a4-40ff-429f-ae05-2d10e8565594" title="A dung beetle is an example of a detritivore" width="500"/><p class="wp-caption-text">Dung Beetle. This dung beetle is rolling a ball of feces to its nest to feed its young.</p></div>
<h3>KQED: Banana Slugs: The Ultimate Recyclers</h3>
<p>One of the most beloved and iconic native species within the old <a data-lesson="population-growth-patterns" data-subject="biology" data-tutorial="ecology-overview" href="https://app.ulearngo.com/biology/ecology-overview/population-growth-patterns">growth</a> redwood forests of California is the Pacific Banana Slug. These slimy friends of the forest are the ultimate recyclers. Feeding on fallen leaves, mushrooms or even dead animals, they play a pivotal role in replenishing the soil. QUEST goes to Henry Cowell Redwoods State Park near Santa Cruz, California on a hunt to find <em>Ariolimax dolichophallus</em>, a bright yellow slug with a very big personality. </p>
<p><iframe allowfullscreen="allowfullscreen" frameborder="0" height="362" src="https://www.youtube.com/embed/i2-qiCqlz8Q?rel=0&amp;modestbranding=1&amp;cc_lang_pref=en&amp;cc_load_policy=1" width="475"><span class="mce_SELRES_start" data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;">﻿</span></iframe></p>
<h2>Summary</h2>
<ul>
<li>Ecosystems require constant inputs of energy from sunlight or chemicals.</li>
<li>Producers use energy and inorganic molecules to make food.</li>
<li>Consumers take in food by eating producers or other living things.</li>
<li>Decomposers break down dead organisms and other organic wastes and release inorganic molecules back to the environment.</li>
</ul>

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Energy Flow

Biology studies life and living organisms. Biology can be divided into different sections that cover the morphology, physiology, anatomy, behavior, and so on of living organisms.

Biology

Discover the intricacies of ecosystems, energy flow, food chains, trophic levels, biomes and climate, vegetation zones in Nigeria, population growth patterns, biodiversity, and environmental issues such as air pollution and global warming.


Energy Flow

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