Food web
Branching lines, not one straight chain.
Who eats the grass?
In a field, an insect eats the grass. A rat eats the grass too. A frog eats the insect, and a bird eats the insect too.
Can a single straight line show who eats whom here?
What this lesson covers
The idea
Each organism is generally eaten by two or more kinds of organisms, which are eaten by several others, so feeding relationships form a series of branching lines, a food web, rather than a straight chain.
Who eats the grass?
In a field, an insect eats the grass. A rat eats the grass too. A frog eats the insect, and a bird eats the insect too.
Can a single straight line show who eats whom here?
- No, the lines branch
- Yes, one straight line is enough
- Yes, the grass is eaten by one kind
Chain or web
Open both tabs.
A web of feeding
Each organism is generally eaten by two or more kinds of organisms, and those are eaten by several others. So the feeding relationships spread out in branching lines instead of one straight line. This is a food web.
Each organism is generally eaten by two or more kinds of organisms, which are eaten by several others, so feeding relationships form a series of branching lines, a food web, rather than a straight chain.
Notes
A food web has branching lines, since an organism is generally eaten by two or more kinds.
Check yourself
How is a food web different from a food chain?
In the picture, which two organisms does the snake eat?
In the picture, what does each arrow show?
In the picture, how many kinds of organisms eat the grass?
Answer: 2
Arrows leave the grass to the rat and to the insect, so 2 kinds eat it.
- It shows one straight line of feeding. A straight line is a food chain. A web has branching lines.
- It shows branching lines, since each organism is generally eaten by two or more kinds of organisms — correct. Yes!
- It has no producers. A food web has producers too. In the picture the grass is a producer.
- Insect and bird. In the picture, the frog and the bird eat the insect, and the snake does not.
- Grass and insect. The grass is eaten by the rat and the insect, and the snake does not eat it.
- Rat and frog — correct. Yes!
- It points from the food to the organism that eats it — correct. Yes!
- It points from the eater to the food. The arrow head is at the eater. The rat, for example, eats the grass, so the arrow points from the grass to the rat.
- It points from the top of the picture down to the bottom. In the picture the arrows run upward or sideways, from each food to its eater. The direction depends on who eats whom.