Answer:
A food web can be formed by more than one food chain, since the webs includes all possible interactions that can occur between individuals of different trophic levels.
Explanation:
Based on the scheme shown in the image
<h3>1. How many food chains make up the food web? </h3>This food network is made up of three food chains
- <em>Plant → Bird → Snake</em>
- <em>Plant → Insect → Bird → Snake</em>
- <em>Plant → insect → Frog → Snake</em>
Food webs often include several food chains, since they are due to the interaction between organisms at different trophic levels, which actually happens within an ecosystem.
<h3> 2. Which organism is an herbivore? </h3>In this case, both the insect and the bird are herbivorous organisms, since they feed of the producer, which is the plant.
<h3> 3. Which organism is an autotroph? </h3>The only autotrophic organism is the plant, since it is capable of manufacturing its nutrients from sunlight and inorganic matter.
<h3> 4. Which organism is a third-order heterotroph? To what trophic level does that organism belong? </h3>The third order heterotroph is the snake, since it feeds on other animals. The snake is a carnivore and can be a secondary or more commonly tertiary consumer, so it can be placed in the 3rd or 4th trophic level.
<h3> 5. Which organism is an omnivore? </h3>According to the scheme proposed, the bird is omnivorous, since it feeds on both plants and insects.
<h3> 6. Which organisms belong to more than one food chain? </h3>In this case, the plant, the insect, the bird and the snake are part of more than one food chain.
- <u><em>Plant → Bird → Snake</em></u>
- <u><em>Plant → Insect → Bird → Snake</em></u>
- <u><em>Plant → insect</em></u><em> → Frog → </em><u><em>Snake</em></u>
The bird can be located in both the second and third trophic level, being a primary consumer —when it feeds on plants— or secondary, when it feeds on insects.
<h3> 8. What are decomposers? From which trophic levels are the organisms that decomposers feed on? </h3>Decomposers are generally bacteria and fungi, organisms capable of degrading organic matter, thus enriching the soil. Decomposers can feed on any trophic level.
<h3> 9. What does a pyramid of energy show about the amount of energy available at different trophic levels of a food chain? </h3>As the ascent of the pyramid occurs —or at the upper trophic level— the amount of energy available decreases. This is because from one trophic level to another only 10% of the energy can be used. If a plant has 5000 Kcal available, the herbivore that consumes it can only use 500 Kcal.
<h3> 10. Why do different trophic levels have different amounts of energy?</h3>The main <u>reason for the difference in energy in each trophic level is that energy is lost in each one of them</u>, which the organisms use in their metabolism. A consequence of the metabolism is the loss of energy as heat, which is acquired by the environment.