Flat and Roundworms Study Guide

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Multiple Choice
Identify the choice that best completes the statement or answers the question.

Planarians can reproduce asexually by

a.	fission.	c.	producing polyps.
b.	forming larvae.	d.	exchanging both sperm and eggs.

Which of the following is not found in flatworms?

a.	an anterior end	c.	bilateral symmetry
b.	a circulatory system	d.	a nervous system

Flatworms have no need for circulatory and respiratory systems because

a.	the digestive system performs these functions.
b.	their cells are close to the animal’s exterior surface.
c.	the spherical body shape allows diffusion of materials into tissues.
d.	the coelom is bathed in blood and oxygen.

Schistosomiasis is a disease caused by a

a.	roundworm.	c.	cestode.
b.	trematode.	d.	planarian.

turbellarians : free-living ::

a.	planaria : parasitic	c.	cestodes : free-living
b.	tapeworms : free-living	d.	flukes : parasitic

Which of the following statements about tapeworms is false?

a.	They can infect a person who eats undercooked food.
b.	They belong to the genus Schistosoma.
c.	They can grow to be large in human intestines.
d.	They do not have a digestive system.

To which phylum do roundworms belong?

a.	Annelida	c.	Platyhelminthes
b.	Nematoda	d.	Arthropoda

Roundworms have a fluid-filled cavity called a

a.	coelom.	c.	digestive system.
b.	pseudocoelom.	d.	None of the above

Roundworms have a digestive tract with ____ opening(s).

a.	three	c.	one
b.	two	d.	no

All of the following groups of invertebrates are coelomates except

a.	annelids.	c.	mollusks.
b.	echinoderms.	d.	nematodes.

A roundworm’s digestive tract can be considered an advancement over a gastrovascular cavity because

a.	food moves through it in only one direction.
b.	different parts of the tract can carry out different functions.
c.	undigested wastes do not have to leave through the same opening where food is taken in.
d.	All of the above

The nematode Ascaris lumbricoides infects humans, spending most of its adult life inside the intestines of its host. To be infected, a person must

a.	consume the nematode’s eggs.
b.	walk barefoot on infested soil.
c.	sit on an infested toilet seat.
d.	All of the above

A type of roundworm that lives a parasitic life is

a.	Ascaris.	c.	Trichinella.
b.	Enterobius.	d.	All of the above

A rotifer uses ____ to collect excess water in order to remove the water from the body.

a.	diffusion
b.	kidneys
c.	flame cells and excretory tubules
d.	a mastax

Which of the following statements is not true?

a.	Most tapeworms are hermaphrodites.
b.	Planarians reproduce both sexually and asexually.
c.	Some rotifers reproduce by parthenogenesis.
d.	Because they are all parasitic, roundworms reproduce asexually.

Tapeworms absorb food from the host through their

a.	scolex.	c.	suckers.
b.	tegument.	d.	None of the above

Humans can avoid trichinosis by

a.	avoiding undercooked meat.
b.	avoiding public restrooms.
c.	wearing shoes outdoors.
d.	washing their hands frequently.

Which of the following has a cloaca?

a.	a fluke	c.	a rotifer
b.	a nematode	d.	a tapeworm

Parasitic flatworms

a.	probably evolved from free-living organisms.
b.	gave rise to free-living flatworms.
c.	have a gut with two openings.
d.	are found mostly in the class Turbellaria.

Which of the following is not true about the planarian nervous system?

a.	It includes a ladderlike arrangement of nerves.
b.	It provides the ability to sense light intensity.
c.	It includes one ventral nerve cord.
d.	It provides the ability to learn.

Completion
Complete each statement.

A schistosome is a member of the phylum ____________________.

The ability of some animals, such as flatworms, to regrow lost parts of their bodies is called ____________________.

Flatworms take up oxygen and release carbon dioxide by the process of ____________________, which occurs across the body surface of the animals.

The ____________________ is a protective cellular covering of the bodies of endoparasitic flukes that prevents them from being digested by their hosts.

____________________ are rectangular body sections of tapeworms.

Roundworms are members of the phylum ____________________.

Roundworms take in food through the mouth and eliminate wastes through an opening at the other end of the digestive tract called the ____________________.

Organisms that feed by using cilia to sweep food into their mouths are called ____________________.

____________________ are the simplest animals with bilateral symmetry.

Concentration of sense organs at the anterior end can be observed in flatworms and is called ____________________.

A planarian takes in food through the ____________________.

The ____________________ is a noncellular layer that protects a roundworm.

Being infected with ____________________ worms can cause a condition known as elephantiasis.

A planarian cannot eat when food is already in its gut. Why? Write your answer in the space below.