Definitions [2]
Definition: Food Chain
A series of organisms where one is eaten by the next and energy flows from producers to consumers is called a food chain.
Definition: Food Web
A network of interconnected food chains showing how various organisms are related through feeding relationships is called a food web.
Key Points
Key Points: Food Chain
- A food chain is a linear sequence of organisms in which food energy is transferred from producers to consumers.
- Every food chain begins with producers (green plants) and usually ends with top consumers that are not preyed upon.
- Energy decreases at each trophic level, so food chains are usually short (not more than five levels).
- Shorter food chains are more stable and efficient, as less energy is lost at each step.
Key Points: Food Web
- A food web is a network of interconnected food chains operating within an ecosystem.
- It shows multiple feeding relationships, as organisms may have more than one food source.
- Food webs represent the flow of energy and nutrients among producers and consumers.
- The complexity of a food web depends on the diversity of organisms and the number of alternative food choices.
Key Points: Waste Management
- Biodegradable substances are broken down by natural biological processes, while non-biodegradable substances cannot be broken down this way and remain in the environment for a long time.
- Many human-made materials like plastics are non-biodegradable and do not decompose easily, leading to long-term pollution.
- Lifestyle changes, such as increased use of disposable items and modern packaging, have led to a rise in non-biodegradable waste.
- Disposable paper cups are better than plastic or clay kulhads because they reduce plastic pollution and avoid the loss of fertile soil caused by making clay cups.
Important Questions [32]
- Study the picture given below showing three food chains (a), (b) and (c) and answer the following questions: Name the type of ecosystems that exist in food chains (b) and (c).
- Which of the Following Are Always at the Second Tropic Level of Food Chains?
- State with Reason Any Two Possible Consequences of Elimination of Decomposers from the Earth.
- "Energy Flow in a Food Chain is Unidirectional" Justify this Statement.
- In a Food Chain of Frog, Grass, Insect and Snake, Assign Trophic Level to Frog.
- Give Reason to Justify the Following: The Existence of Decomposers is Essential in a Biosphere.
- Give Reason to Justify the Following: Flow of Energy in a Food Chain is Unidirectional.
- List Two Biotic Components of a Biosphere.
- Why Are Green Plants Called Producers?
- The First Trophic Level in a Food Chain is Always a Green Plant. Why ?
- List Two Main Components of Ecosystem?
- We Do Not Clean Natural Ponds Or Lakes but an Aquarium Needs to Be Cleaned Regularly. Why is It So ? Explain.
- List two important roles play in the environment by decomposers.
- "Our food grains such as wheat and rice, the vegetables and fruits and even meat are found to contain varying amounts of pesticide residues." State the reason to explain how and why it happens?
- In the following food chain, 100 J of energy is available to the lion. How much energy was available to the producer? Plants → Deer → Lion
- In the following food chain, plants provide 500 J of energy to rats. How much energy will be available to hawks from snakes? Plants → Rats → Snakes → Hawks
- In the following food chain, 20,000 J of energy was available to the plants. How much energy would be available to man in this chain?
- Explain How the Pesticides Enter a Food Chain and Subsequently Get into Our Body.
- What Are the Various Steps of Food Chain Called?
- What is a trophic level?
- Write the percentage of energy transferred from autotrophs to the next level in a food chain.
- Your mother always thought that fruit juices are very healthy for everyone. One day she read in the newspaper that some brands of fruit juices in the market have been found to contain certain level of
- "Energy flow in food chains is always unidirectional". Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.
- Human body is made up of five important components, of which water is the main component. Food, as well as potable water, are essential for every human being.
- What are decomposers? What will be the consequence if the decomposers are completely eradicated from an ecosystem? Give justification in support of your answer.
- In the following food chain, only 2J of energy was available to the peacocks. How much energy would have been present in Grass? Justify your answer.
- Use of several pesticides which results in excessive accumulation of pesticides in rivers of ponds, is a matter of deep concern. Justify this statement.
- What Will Be the Amount of Energy Available to the Organisms of the 2nd Trophic Level of a Food Chain If the Energy Available at the First Trophic Level is 10,000 Joules?
- Assertion (A) : The energy which passes to the herbivores does not come back to autotrophs. Reason (R) : The flow of energy in a food chain is unidirectiona.
- If a harmful chemical enters a food chain comprising peacocks, plants, rats and snakes, which of these organisms is likely to have the highest concentration of the chemical in its body?
- Draw a diagram showing flow of energy from solar input to a food chain having four trophic levels in an ecosystem. List two inference that can be drawn from the energy flow diagram.
- Study the given figure of a Food web and identify the primary consumer in the food web:
