Download Characteristics of Worms (pages 26–27)

Name
Date
Sponges, Cnidarians, and Worms
Worms
■
Class
Adapted Reading and Study
(pages 26–32)
Characteristics of Worms
(pages 26–27)
Key Concept: Biologists classify worms into three
major phyla—flatworms, roundworms, and segmented
worms.
• The three main groups of worms are flatworms,
roundworms, and segmented worms.
• Worms are invertebrates because they do not have a
backbone. Worms have bilateral symmetry. Worms have
cells, tissues, organs, and systems.
• Worms have a brain and sense organs.
• Some worms reproduce sexually. Some worms
reproduce asexually.
Answer the following questions. Use your textbook and the
ideas above.
1. Circle the letter of each sentence that is true about
worms.
a. There are three main groups of worms.
b. Worms have radial symmetry.
c. Worms have a brain.
2. Is the following sentence true or false? All worms
reproduce asexually.
3. Circle the letter of each term that tells about worms.
a. invertebrate
b. bilateral symmetry
c. vertebrate
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14
Name
Date
Sponges, Cnidarians, and Worms
Flatworms
■
Class
Adapted Reading and Study
(pages 28–29)
Key Concept: Flatworms are the simplest group of
animals with bilateral symmetry. They are flat, as soft
as jelly, and mostly parasitic.
• Flatworms are one of the three groups of worms.
• Some flatworms are parasites. Parasites live on or in
another organism called a host. Parasites take food
from the host. Tapeworms are flatworms that are
parasites.
• Some flatworms are free-living. Free-living organisms
do not live on or in a host. Free-living flatworms live in
water or wet soil.
• Planarians are a kind of flatworm. They are free-living
scavengers. Scavengers eat dead or decaying things.
Planarians also eat other small animals.
Answer the following questions. Use your textbook and the
ideas above.
4. Draw a line from each term to its meaning.
Term
Meaning
free-living
a. takes food from a host
parasite
b. eats dead and decaying things
c. does not live in or on a host
scavenger
5. Circle the letter of the word that tells what a parasite
lives on.
a. scavenger
b. host
c. larva
6. Organisms that do not live in or on a host are called
.
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
15
Name
Date
Sponges, Cnidarians, and Worms
Roundworms
■
Class
Adapted Reading and Study
(page 30)
Key Concept: Unlike cnidarians or flatworms,
roundworms have a digestive system that is like a
tube, open at both ends.
• Roundworms are one of the three groups of worms.
Roundworms live in many places.
• Some roundworms are parasites. Other roundworms
are free-living.
• Roundworms have a digestive system that is open on
both ends. Food goes into the mouth and moves
through the body. Waste leaves through the anus, an
opening at the other end.
Answer the following questions. Use your textbook and the
ideas above.
7. Circle the letter of each sentence that is true about
roundworms.
a. Some roundworms are parasites.
b. Roundworms have a digestive system with two
openings.
c. Roundworms can live in only one place on Earth.
8. Read each word in the box. In the sentences below, fill
in the correct words.
tube
mouth
anus
Food enters a worm’s body through the
. The food moves through the
body. Waste leaves the worm’s body through the
.
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
16
Name
Date
Sponges, Cnidarians, and Worms
■
Class
Adapted Reading and Study
Segmented Worms
(pages 31–32)
Key Concept: Segmented worms have bodies made
up of many linked sections called segments.
• Segmented worms are one of the three groups of
worms. Segmented worms have bodies made of many
parts joined in a row. Earthworms are one kind of
segmented worm.
• Segmented worms have a digestive system that is open
on both ends. They have a mouth and an anus.
• Segmented worms have a closed circulatory system.
Blood stays inside tubes in their bodies.
• Earthworms make tunnels in soil. The tunnels make the
soil better for plants. Earthworm wastes also make soil
better for plants.
Answer the following questions. Use your textbook and the
ideas above.
9. Circle the letter of each sentence that is true about
segmented worms.
a. Segmented worms do not have a mouth.
b. Segmented worms have a closed circulatory
system.
c. An earthworm is a segmented worm.
10. Look at the pictures. Circle the picture that shows a
segmented worm.
© Pearson Education, Inc., publishing as Pearson Prentice Hall. All rights reserved.
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