Food Chains and Food Webs Worksheet

Modular Distance Learning in Science 7 Name: _____________________________________________ Section: ___________________ Objective: Students will analyze and construct food chains and food webs to understand energy flow and relationships within ecosystems. A food chain is a direct pathway of consumption and energy transfer. It shows the order in which organisms eat each other, with producers at the bottom, primary consumers next, and secondary and tertiary consumers at the top. While, food web is a more realistic representation of consumption relationships in an ecosystem. It shows how food chains intertwine, and that most organisms are consumed by or consume more than one species. Task 1: Create a food chain connection using the following organisms below: Bacteria Snake Heron Grass Rat Answer: Answer: Task 2: Identify and label organisms in a simple food chain. Use the different organisms below to label the roles of each organism (Producer, Primary Consumer, Secondary Consumer, Tertiary Consumer) Grass → Grasshopper → Frog → Snake → Eagle Guide Questions: What is the role of grass in the food chain? ____________________________________________________ What does the arrow represent in a food chain? ____________________________________________________ Which organism is the top predator in this chain? ____________________________________________________ Task 3: Understanding of food webs, their components, and their importance in ecosystems. Instructions: Read each question carefully. Choose the best answer by writing the letter of your choice on the space provided before each number. ______ 1. What does a food web represent in an ecosystem? A. The amount of sunlight each organism receives. B. The interconnections of multiple food chains. C. The number of organisms in a habitat. D. The physical traits of predators and prey. ______ 2. Which of the following is always at the base of a food web? A. Herbivores B. Decomposers C. Producers D. Carnivores ______ 3. In a food web, arrows point from one organism to another. What does the arrow represent? A. The size of the organisms. B. The direction of energy flow. C. The speed of energy transfer. D. The relationship between predator and prey. ______ 4. If the population of rabbits decreases in a food web, which of the following might occur? A. Grass growth will increase. C. The snake population will decrease. B. Hawks will increase in number. D. Decomposers will stop working. ______ 5. Which of the following organisms is a decomposer in a food web? A. Rabbit B. Grass C. Mushroom D. Hawk ______ 6. In a food web, an animal that eats both plants and other animals is called a ___ A. Herbivore B. Carnivore C. Omnivore D. Decomposer ______ 7. What would most likely happen if all producers were removed from a food web? A. Consumers would thrive. C. The entire food web would collapse. B. Decomposers would replace them. D. Energy would flow in reverse. ______ 8. In a food web, a hawk is most likely to be which of the following? A. Producer B. Primary consumer C. Secondary or tertiary consumer D. Decomposer ______ 9. Which of the following best describes why food webs are more realistic than food chains? A. They show the exact number of organisms in an ecosystem. B. They represent the variety of feeding relationships in an ecosystem. C. They always include all decomposers. D. They are easier to draw than food chains. ______ 10. Which of the following is an example of a food web disruption caused by human activity? A. A tree falling in the forest. C. Seasonal changes in temperature. B. Overhunting a predator species. D. The natural migration of herbivores. Task 4: Analyze the effects of removing an organism from a food web. Scenario: "What happens if all snakes are removed from the ecosystem?" Instructions: Write a short paragraph predicting the changes in population and energy flow. Guide Questions: Which populations will increase? ______________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ Which populations will decrease? ______________________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________ How will the balance of the ecosystem change? __________________________________________________________ _________________________________________________________________________________________________ _________________________________________________________________________________________________