Organisms are dependent on each other for a source of energy. Producers rely on the Sun, consumers rely on producers and smaller prey earlier in the chain, and final consumers need weaker animals to feed on. Each organism has a role to play, and the others will not survive if one link in the chain goes missing.

The Department of Education and Training for Victoria State in Canada explains in scientific terms how energy is transferred through the food chain when all the necessary organisms are present, "Energy is transferred between organisms in food webs from producers to consumers. The energy is used by organisms to carry out complex tasks. The vast majority of energy that exists in food webs originates from the sun and is converted (transformed) into chemical energy by the process of photosynthesis in plants. A small proportion of this chemical energy is transformed directly into heat when compounds are broken down during respiration in plants. The majority of the chemical energy stored in plants is transformed into other forms by an assortment of consumers, such as cows, rabbits, horses, sheep, caterpillars, and other insects eating plants. Some of the stored chemical energy in a producer such as grass is stored as chemical energy in the fat or protein in the first-order consumers that eat the grass. This energy is available for higher-order consumers. At each stage of a food chain, most of the chemical energy is converted to other forms such as heat and does not remain within the ecosystem." If organisms are missing from the food chain, animals can adapt by finding another source of energy, conserving energy, moving locations, or they will not survive.

Source: https://www.education.vic.gov.au/school/teachers/teachingresources/discipline/science/continuum/Pages/ecosystem.aspx#:~:text=Energy%20is%20transferred%20between%20organisms,process%20of%20photosynthesis%20in%20plants.

Animals that hunt and eat other animals are called carnivores. This means they eat only meat. Animals like hawks, sharks, lions, and owls are examples of carnivores. They have specially adapted features to allow them to excel at hunting and eating meat. Strong talons, sharp beaks, sharp teeth, powerful jaw, and night vision are just a few adaptations. They still receive energy from the Sun and producers as they consume other animals in the food chain, but they do not directly eat the producers.

This food chain shows a producer (grass), then a mouse, which is an herbivore, and a snake, which is a consumer. Whichever consumer comes after, the snake must be a predator to the snake. The Golden Eagle is a predator to the snake and could eat it. Energy is passed along the food chain from each organism to the next.

Each organism in the food chain plays a specific role and has a title. The grass is a producer and creates its food, using sunlight, water, and carbon dioxide. A mouse in this food chain would be the primary consumer. A secondary consumer eats the primary consumer, so it would be the snake. The hawk is the final consumer and the top predator in the food chain. The mushrooms represent the decomposer that breaks down waste from animal and plant remains.

The term abiotic means something that is not living; it is devoid of life. Abiotic materials are still part of an ecosystem, but they are not living organisms. Of the answer choices, only one is a nonliving thing, a rock. The other options are all living organisms and are biological rather than physical.

All consumers, producers, and decomposers are biotic. This means that they are all living, biological organisms. Biotic factors in an ecosystem or food chain can describe either the consumer or the producer. Decomposers are also living things and fall into the category of biotic.

Omnivores are organisms that eat both plant and animal products. Humans are an example of an omnivore because we eat meat like beef, pork, fish, and chicken and eat fruits and vegetables, which are plants or plant by-products. A carnivore only eats animal products (like a cheetah), and herbivores only eat plants and plant by-products (like a rabbit).