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Science experiment
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Student focus question:
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Teachers notes l cl as s ific a
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What are some features scientists use to classify animals?
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Scientists classify all living things into five kingdoms—monerans, protists, fungi, plants and animals. In many ways, the animal kingdom seems more complex than the other kingdoms. There are more subdivisions within the animal kingdom and more animal species have been identified. The main idea upper primary students should learn is that scientists classify living things based on their external physical characteristics—e.g. shape, number of appendages, body covering—as well as their internal structure; e.g. skeleton, complexity of organ systems, method of reproduction.
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Students should note on their ‘Animal classification chart’ on page 22 that all of the animals except the fish are invertebrates. The sponge and earthworm have no legs. The sponge may feel soft, springy or slightly rough (depending on the type).
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The earthworm should feel soft, smooth and moist. Careful observation might reveal tiny whiskers (called setae) on the underside, which aid in crawling.
© R. I . C.Publ i cat i ons •f orr evi ew pu r posesonl y• • Students should be able to observe that
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The holes in the sponge allow water to pass through. The water is filtered to remove tiny plant and animal food.
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As you progress up through the vertebrates, the internal structures become better developed and more complex. That is why mammals are considered the highest form of animal life.
For the experiment, it will be easier if you place the fish on the disposable plate and the earthworm in a small dish and cover it with plastic wrap before you distribute these materials to the student groups. Sea sponges are available at art and hardware stores and you can find earthworms at most gardening stores (as well as in the garden!). Ask the fishmonger at the market to cut the fish in half lengthwise.
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spiders have two sections to their body, eight legs (which are attached to the head section) and no antennae; whereas, insects have three sections to their body, six legs (attached to the midsection or thorax) and antennae.
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Simple invertebrates, like sponges and jellyfish, have bodies made of only two layers of cells and no developed organ systems. Worms are a little more complex. They have simple nervous and digestive systems. Annelid worms are more advanced. They have circulatory, excretory and reproductive systems as well.
Literacy through science
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In addition to the different number of body parts, in Question 2, students most likely will indicate that insects have antennae whereas spiders do not. They might also mention that insects have large compound eyes and spiders have several simple eyes (usually about eight).
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Fish are covered with wet scales, which provide protection. The fish is classified differently from all of the other animals because it has a backbone; it is a vertebrate animal. The fish’s gills are used for breathing.
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Students should conclude that scientists use external physical features as well as internal structural features to classify animals. R.I.C. Publications® – www.ricpublications.com.au