Week 10 · Chapter 8 Egypt Special Part 1: 8-1 Desert and Nile Food Chains; Let’s Expand; Column: It Always Starts with “Plants” · 3 lessons
1
Who rules the Nile food chain?
Science P6: Term 1, Chapter 8, pp. 68–73
GoalTrace the Nile food chain from the water plants to the top animal.
New words
algae · very small plant-like living things that float in watertop carnivore · the last animal in a chain, which few animals eatNile tilapia · a common fish in the Nile
Explanation
The Nile is full of life. The chain starts with the producers: algae and water plants use sunlight to make food. Small animals and fish, such as the Nile tilapia, eat the algae and plants. A bigger fish, the Nile perch, eats smaller fish. At the top of the chain is the Nile crocodile, a large carnivore that eats fish and other animals. Each arrow points from the food to the eater. A chain does not tell the whole story, because most animals eat more than one thing. In the Nile, many chains join to make a food web. People are part of it too: farmers and fishers use the river for food.
algae and water plants→Nile tilapia→Nile perch→Nile crocodile
Worked examples
Living thing
Role
algae
producer
Nile tilapia
herbivore
Nile perch
carnivore
Nile crocodile
top carnivore
Hana follows the Nile chain: the algae are producers, the tilapia is a herbivore, and the perch and the crocodile are carnivores.
Youssef thinks: if the tilapia decreased, what would happen? The algae might grow more, and the perch would find less food. A change in one link affects others.
A fisherman on a felucca catches tilapia. He eats the fish. A person is also part of the food chain of the Nile.
Class activity
Chain building. With a grown-up, write the four Nile animals and plants on cards. Put them in the right order and add arrows pointing from food to eater. Then add one more card of your own, such as a water bird, and say where it joins the web.
Practice
1
What are the producers in the Nile chain?
Algae and water plants.
2
Which animal eats the Nile perch in the chain?
The Nile crocodile.
3
Draw an arrow between tilapia and perch. Which way does it point?
From the tilapia to the perch (food to eater).
4
Why is a chain a simple picture of a bigger food web?
