Nematoda
Roundworms with a body that has two openings.
A thin round worm
A roundworm has a long, thin, cylindrical body.
Where do you think such a body can move well?
What this lesson covers
The idea
Roundworms have elongated cylindrical bodies that move efficiently through soil, water or host tissues, a body with two openings (mouth and anus), and separate male and female worms.
A thin round worm
A roundworm has a long, thin, cylindrical body.
Where do you think such a body can move well?
- Through soil, water or host tissues
- Only in the air
- Only on very hard rock
Roundworm features
Open each tab.
A good design
The roundworm body is simple inside but works well. It lets roundworms live in a wide range of environments. They have a mouth and an anus, and male and female worms are separate.
Roundworms have elongated cylindrical bodies that move efficiently through soil, water or host tissues, a body with two openings (mouth and anus), and separate male and female worms.
Notes
Roundworms (Nematoda) have cylindrical bodies, two openings (mouth and anus) and separate male and female worms.
Check yourself
What is the shape of a roundworm's body?
How many openings does a roundworm body have?
Through which places can roundworms move efficiently?
What is true of male and female roundworms?
- Elongated and cylindrical — correct. Yes!
- Flat like a leaf. Flat bodies are shown by flatworms.
- Vase-shaped with pores. Pores are a feature of sponges.
- One for both food and waste. A single opening is found in cnidarians and flatworms.
- Two, a mouth and an anus — correct. Yes!
- Many pores. Numerous pores are found in sponges.
- Only through the air. Roundworms move through soil, water or host tissues.
- Only along hard branches. The book names soil, water and host tissues.
- Soil, water or host tissues — correct. Yes!
- They are separate worms — correct. Yes!
- One worm is both. The book says male and female worms are separate.
- They look exactly like sponges. Roundworms have cylindrical bodies and are not sponges.