Food Webs and Food Chains Worksheet worksheet - Free Printable

Let's go through each question step by step based on the food web provided in the image. We'll analyze the relationships and answer each question with clear explanations.

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1) Which of the following is an omnivore?

a) Bird
b) Snake
c) Mongoose
d) Rat

✔ Answer: d) Rat

🔹 Explanation:
An omnivore eats both plants and animals. In this food web:
- The Rat eats seeds and nuts (plants) and is eaten by mongoose and snake, but it also consumes other things not shown here, suggesting it might eat both plant and animal matter.
- The Bird eats caterpillars (animals), so it’s a carnivore.
- The Snake eats birds, rabbits, rats — all animals → carnivore.
- The Mongoose eats rats → carnivore.

So, Rat is the only one that clearly consumes both seeds/nuts (plant material) and possibly other food sources — making it omnivorous.

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2) How many apex predators are shown on this food web?

✔ Answer: 1

🔹 Explanation:
An apex predator is at the top of the food chain and has no natural predators.

In this web:
- Hawk eats snake, mongoose, and rat.
- No animal eats the Hawk.
- So, Hawk is the only apex predator.

Even though Snake and Mongoose are higher up, they are preyed upon by the Hawk.

👉 Therefore, only one apex predator: Hawk.

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3) List three herbivores shown on the food web.

✔ Answers:
1) Rabbit
2) Caterpillar
3) Rat *(if eating seeds/nuts)*

🔹 Explanation:
Herbivores eat only plants or plant parts.

- Rabbit → eats plants
- Caterpillar → eats plants
- Rat → eats seeds and nuts (which are plant products)

Note: While Rat may be omnivorous, in this diagram, it's shown consuming only seeds and nuts, so it can be considered a herbivore here.

Alternatively, if you're strict about omnivory, you could list:
- Rabbit
- Caterpillar
- Possibly Bird? No — bird eats caterpillar → carnivore.

So best answers:
1) Rabbit
2) Caterpillar
3) Rat

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4) What would happen to the Snake population if the Rabbit became extinct?

✔ Answer:
The Snake population would decrease because rabbits are a food source for snakes. Without rabbits, snakes would have less food, leading to starvation, lower reproduction rates, and a decline in their population.

🔹 Explanation:
Snakes eat rabbits, birds, and rats. If rabbits go extinct, snakes lose one of their food sources. This could reduce snake numbers unless they can fully adapt to other prey (like birds or rats). But since there’s no indication of increased availability of other prey, we assume the snake population will decline due to reduced food supply.

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5) Where does the Hawk get its energy from?

✔ Answer:
The Hawk gets its energy from the animals it eats, such as snakes, mongooses, and rats.

🔹 Explanation:
Energy flows through the food web from producers (plants) to consumers. Hawks are top predators, so they get energy from eating other animals (secondary or tertiary consumers). Specifically:
- Hawk eats Snake → Snake eats rabbit/bird/rat → which eat plants.
- Hawk eats Mongoose → Mongoose eats rat → rat eats seeds.
- Hawk eats Rat directly.

So, the hawk gets energy indirectly from plants via the food chain, but directly from animals it consumes.

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6) Which of the following is a food chain shown in the web above?

a) Plants → Bird → Snake → Hawk
b) Plants → Rabbit → Snake → Hawk
c) Plants → Caterpillar → Mongoose → Hawk
d) Plants → Caterpillar → Rat → Hawk

✔ Answer: b) Plants → Rabbit → Snake → Hawk

🔹 Explanation:
Check each option against the arrows in the web:

- a) Plants → Bird → Snake → Hawk
- Bird eats caterpillar, not plants → Invalid

- b) Plants → Rabbit → Snake → Hawk
- Rabbit eats plants ✔
- Snake eats rabbit ✔
- Hawk eats snake ✔
→ Valid chain

- c) Plants → Caterpillar → Mongoose → Hawk
- Caterpillar eats plants ✔
- But Mongoose does NOT eat caterpillars — it eats rats → Invalid

- d) Plants → Caterpillar → Rat → Hawk
- Rat doesn't eat caterpillars — Rat eats seeds/nuts → Invalid

✔ Only b is correct.

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7) What would happen to the Plant population if the Caterpillar population decreased?

✔ Answer:
The Plant population would increase because caterpillars are herbivores that feed on plants. Fewer caterpillars mean less consumption of plants, so more plants survive and grow.

🔹 Explanation:
Caterpillars are primary consumers that eat plants. If their population drops, predation pressure on plants decreases, allowing plants to reproduce and expand.

This is an example of trophic cascade: removing a consumer leads to an increase in the producer population.

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8) List the carnivores shown in this food web.

✔ Answer:
- Hawk
- Snake
- Mongoose
- Bird

🔹 Explanation:
Carnivores eat other animals.

- Hawk → eats snake, mongoose, rat
- Snake → eats bird, rabbit, rat
- Mongoose → eats rat
- Bird → eats caterpillar

Note: Rat is omnivore (eats seeds AND possibly other things), but in this web, it's shown eating seeds → mainly herbivore.

So carnivores are:
1) Hawk
2) Snake
3) Mongoose
4) Bird

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✔ Final Answers Summary:

1) d) Rat
2) 1
3) 1) Rabbit, 2) Caterpillar, 3) Rat
4) The snake population would decrease due to loss of a food source.
5) The Hawk gets its energy from eating snakes, mongooses, and rats.
6) b) Plants → Rabbit → Snake → Hawk
7) The plant population would increase due to reduced predation by caterpillars.
8) Carnivores: Hawk, Snake, Mongoose, Bird

Let me know if you'd like this formatted as a printable answer sheet!