Educational worksheet on food webs and food chains, featuring diagrams and questions to teach ecological relationships.

Let's solve the Food Webs and Food Chains Worksheet step by step and explain each answer clearly.

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1. Look at this food chain:

lettuce → greenfly → ladybird → thrush → cat

#### a) What does the arrow mean in a food chain?
✔ The arrow shows the direction of energy flow — it points from the organism being eaten to the organism that eats it.
In other words, the arrow indicates "is eaten by."

> Example: The greenfly is eaten by the ladybird.

#### b) Name the producer in the food chain.
✔ Lettuce
Producers are organisms that make their own food through photosynthesis (like plants). Lettuce is a plant, so it’s the producer.

#### c) Name the third trophic level in the food chain.
✔ Ladybird
Trophic levels:
- 1st: Producer → lettuce
- 2nd: Primary consumer → greenfly (eats lettuce)
- 3rd: Secondary consumer → ladybird (eats greenfly)

So, the third trophic level is the ladybird.

#### d) Name the tertiary consumer in the food chain.
✔ Thrush
Tertiary consumers eat secondary consumers. Here:
- Thrush eats ladybird (secondary consumer), so thrush is the tertiary consumer.
- Cat eats thrush → quaternary consumer.

So, thrush is the tertiary consumer.

#### e) What is the ultimate source of energy that drives the food chain?
✔ The Sun
All food chains begin with energy from the sun, which producers (like lettuce) use in photosynthesis to make food. This energy then moves up the chain.

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2. Look at these food chains:

Given food chains:
- grass → slug → thrush → cat
- grass → slug → fox
- grass → rabbit → fox
- grass → rabbit → cat

Now we need to build a food web using these chains.

We are given an image with some animals: fox, cat, thrush, slug, grass, rabbit.

One arrow is already drawn: slug → thrush

Let’s now fill in the arrows based on the food chains.

#### a) Use the food chains to help you fill in the arrows on this food web.

From the chains:
- grass → slug → both slugs eat grass
- slug → thrush → thrush eats slug
- thrush → cat → cat eats thrush
- slug → fox → fox eats slug
- grass → rabbit → rabbit eats grass
- rabbit → fox → fox eats rabbit
- rabbit → cat → cat eats rabbit

So, draw arrows as follows:

- Grass → Slug
- Grass → Rabbit
- Slug → Thrush
- Slug → Fox
- Thrush → Cat
- Rabbit → Fox
- Rabbit → Cat

This creates a food web where:
- Grass is at the base
- Slugs and rabbits feed on grass
- Thrush and fox eat slugs
- Fox and cat eat rabbits
- Cat also eats thrush

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#### b) Name the producer in this food web.
✔ Grass
It's the only organism that makes its own food via photosynthesis.

#### c) Name a consumer in this food web.
✔ Any of: slug, rabbit, thrush, fox, cat
(Any animal that eats other organisms is a consumer.)

#### d) What eats rabbits?
✔ Fox and cat
From the food chains:
- grass → rabbit → fox
- grass → rabbit → cat

So, fox and cat both eat rabbits.

#### e) What does a fox eat?
✔ Slugs and rabbits
From the food chains:
- grass → slug → fox
- grass → rabbit → fox

So, fox eats slugs and rabbits.

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✔ Final Answers Summary:

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Question 1:
a) The arrow means "is eaten by" or shows the direction of energy flow.
b) Producer: lettuce
c) Third trophic level: ladybird
d) Tertiary consumer: thrush
e) Ultimate source of energy: the Sun

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Question 2:
a) Arrows should be:
- Grass → Slug
- Grass → Rabbit
- Slug → Thrush
- Slug → Fox
- Thrush → Cat
- Rabbit → Fox
- Rabbit → Cat

b) Producer: grass
c) Consumer: any one of slug, rabbit, thrush, fox, cat (e.g., rabbit)
d) What eats rabbits? Fox and cat
e) What does a fox eat? Slugs and rabbits

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Let me know if you'd like a visual sketch of the completed food web!