Study P6 Science Food Chains: Roles and Relationships - Geniebook

# Food Chains: Roles And Relationships

In this article, you will be introduced to food chains according to the Singapore Primary 6 Science Syllabus.   We will focus on the following:

• type of food that different animals feed on
• predator-prey relationship
• food chain
• decomposers

## What is a food producer?

A food producer is an organism that makes its own food. Plants are examples of food producers as plants are able to make their own food by the process of photosynthesis.  Plants are able to make their own food because they contain chlorophyll to trap light energy from the Sun to provide them with the energy to make food. Photosynthesis is the process whereby carbon dioxide and water is taken in by the plants in the presence of sunlight to make food and release oxygen at the same time.  The food made by the plants are the energy source for them to carry out their life processes. The food producers is usually the largest in population size in a food chain.

## What are food consumers?

Food consumers are organisms that consume food in order to obtain energy.  Different food consumers feed on different types of food. The food consumers can be grouped into the following: herbivores, omnivores and carnivores.

A herbivore or a plant-eater is an animal that feeds on plants for food. An omnivore or a plant-and-animal eater is an animal that feeds on both plants and animals for food.  A carnivore or an animal-eater is an animal that feeds on animals for food.

## What is a predator and a prey?

A predator is an animal that obtains its food primarily by consuming other animals.

A prey is an animal that other animals hunt for food.

Predator

Prey

bear

fish

lion

zebra

fox

rabbit

## What is a food chain?

A food chain shows how the organisms are related to each other by the food that they eat in the ecosystem.  It also shows the energy transfer from one organism to the next organism.  A food chain shows how each organism is dependent on each other for survival.  The balance in nature is important to ensure survival of the organisms. This creates more awareness on our actions to the environment that may cause an impact on their survival.

A food chain always begins with a food producer (plant). The energy from the food producer is being passed down or transferred to the organisms that consumed it.

#### How to write a food chain?

An arrow (→) is used to represent ‘consumed by’ or ‘energy transferred’.

For Example:

The deer feeds on the cow grass while the lion feeds on the deer.  The food chain will be as follows:

$$\textbf{cow grass } \xrightarrow[]{\quad\textit{ eaten by }\quad} \textbf{ deer } \xrightarrow[]{\quad\textit{ eaten by }\quad} \textbf{ lion}$$

Do take note that the Sun is not part of a food chain even though food producers or the plants take in energy from the sun to make food.

## Fun Fact: Carnivorous Plant - Producer or Consumer?

Carnivorous plants are plants that eat small animals and insects.

Carnivorous plants are food producers as they are able to make their own food through photosynthesis.  However, these plants grow in soil that is poor in nutrients.  In order to survive in their harsh environment, they have to feed on other organisms to obtain sufficient nutrients to survive better in their environment.

Examples Of Carnivores:

## Decomposers

Have you ever wondered why the forest and jungles are not littered with fallen leaves or remains of dead animals?

This is due to a group of organisms known as decomposers.  Decomposers help to break down the dead organisms such as plants and animals into simpler substances and return them back to the soil as nutrients for the plant through a process known as decomposition.  Examples of decomposers are fungi and bacteria.

Decomposition is the process whereby dead organic matter is broken down into simpler substances such as carbon dioxide, water and minerals that are important for the survival of plants.   Plants take in the carbon dioxide and water for photosynthesis and minerals for them to grow well.

## Conclusion

In this article,  we learnt about food chains and decomposers. We also explored the different types of food consumers such as herbivores (plant eaters), omnivores (plant-and-animal eaters) and carnivores (animal eaters) and the predator-prey relationship among the animals.

## Test Your Concepts

Answer the following questions based on the concepts we’ve covered in this article. If you are unclear, you may want to revisit the relevant section to revise the concepts.

Question 1:

The following shows some examples of how energy is transferred from one living thing to another.

maize  →     rat     →   owl

grass   →    deer   →   lion

carrot   →   rabbit  →   fox

Based on the food chains above, which of the following statements about energy transfer are correct?

1. The lion gets energy directly from the grass.
2. The fox gets energy directly from the rabbit.
3. The transfer of energy always begins with the Sun.
4. The main source of energy for the food chains is plant.

1. A and B only
2. B and C only
3. B and D only
4. A and D only

Solution:

(2) B and C only

Explanation:

Statement A is incorrect as the lion gets its energy indirectly from the tree.

Statement D is incorrect because the Sun is the main source of energy for all organisms.

Question 2:

The food chain below shows how energy is being transferred from the algae to different animals.

algae  →  zooplankton  →  small fish  →  large fish  →  shark

Based on the food chain above, which of the following statements are true?

1. The shark gets energy directly from the large fish.
2. The zooplankton gets energy directly from the algae.
3. The large fish gets energy indirectly from the small fish.
4. The zooplankton is the only food producer in the food chain.

1. A and B only
2. C and D only
3. A, B and C only
4. A, B, C and d

Solution:

(A) A and B only

Explanation:

Algae is the only food producer in the food chain.

The large fish gets energy directly from the small fish.

Question 3:

Michael came up with the following statements regarding decomposers.

1. They help make the soil fertile.
2. They make their own food and purify the air.
3. They help to get rid of dead organisms and wastes.
4. They speed up the process of decomposition by breaking down plant and animal wastes into smaller pieces.

Which of the statements made by Michael are correct?

1. A and C only
2. A and D only
3. B and C only
4. B and D only

Solution:

(A) A and C only

Explanation:

Decomposers help to make soil fertile by breaking dead plants and animals into simpler substances which are returned back to the soil as nutrients for the plants.  Decomposers do not make their own food as they do not have chlorophyll.

Question 4:

Which of the following statements about decomposers is/are true?

1. Bacteria and fungi are decomposers.
2. Decomposers enrich the soil with nutrients for plants to grow.
3. Decomposers break down dead matter and animal waste into smaller pieces.

1. A only
2. A and B only
3. B and C only
4. A, B and C

Solution:

(2) A and B only

Explanation:

Bacteria and fungi are decomposers which help to break down dead organic matter into simpler substances that are returned back to the soil as nutrients for the plants.

Continue Learning
Interaction: Introduction to Force Living Together
The Environment And Relationships Food Chains: Roles And Relationships
Interaction Of Forces: Friction Food Webs: Roles And Relationships
Energy In Food

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Primary
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Interaction: Introduction to Force
Living Together
The Environment And Relationships
Food Chains: Roles And Relationships
Interaction Of Forces: Friction
Food Webs: Roles And Relationships
Energy In Food
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