Six things happen in a park. A girl swims across a pool…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
Six things happen in a park.
- A girl swims across a pool.
- Cilia move mucus up the windpipe of a man.
- A bird flies from one tree to another.
- The tentacles of a Hydra catch a water flea, and the animal stays where it is.
- The heart of a runner beats faster.
- A bull runs across a field.
Which of them are locomotions? For each of the others, say why it is a movement only.
Need a reminder? The key ideaShow
Movement is any change in the position of the body or of a part of it. Locomotion is a voluntary movement that changes the place of the whole body. The kinds of movement are amoeboid, ciliary, flagellar and muscular. About to of the body weight of an adult is muscle.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. Six events.
Plan. Test each one with the definition: voluntary, and the whole body changes place.
Step 1. (a), (c) and (f). The girl swims, the bird flies and the bull runs. Each is voluntary, and each carries the whole body from one place to another. These are locomotions.
Step 2. (b). The cilia sweep the mucus, but the man stays where he is. This is a movement only.
Step 3. (d). The tentacles move, but the Hydra stays where it is. This is a movement only.
Step 4. (e). The heart beats, but this is not voluntary, and the runner is not changed in place by it. This is a movement only.
Answer: (a), (c) and (f) are locomotions. (b), (d) and (e) are movements only.
Check. Every locomotion is also a movement, so (a), (c) and (f) are movements as well.
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