Section 27-1

Question 1

Flatworms make up the phylum _________

Answer 1

Plathelminthes

Question 2

What are the defining features of flatworms

Answer 2

They are soft, flattened worms that have tissues and internal organ systems. They are the simplest animals to have three embryonic germ layers, bilateral symmetry and cephalization

Question 3

A fluid filled cavity that is lined with tissue derived from mesoderm is called a ___________

Answer 3

Coelom

Question 4

Why are flat worms known as acoelomates??

Answer 4

Because they don’t have a coelom

Question 5

Is the following sentence true or false? Flatworms are the simplest animals to have three germ layers

Answer 5

True

Question 6

Circle the letter of each sentence that is true about falt worms
A.) Parasitic species are typically simpler in structure than free living species
B.) Freeliving flatworms have organ systems for digestion, excretion, response, and reproduction
C.) Freeliving species probably evolved from parasitic ancestors
D.) All flatworms rely on diffusion for some essential functions

Answer 6

A
B
D

Question 7

What do freeliving flatworms feed on?

Answer 7

They can be carnivores and feed on tiny aquatic animals or recently dead animals

Question 8

A muscular tube near the mouth at the end of the gastovascular cavity is called a _________

Answer 8

Pharynx

Question 9

What is the function of the pharynx?

Answer 9

Flatworms extend the pharynx out of the mouth. The pharynx then pumps food into the digestive cavity or gut

Question 10

What are flame cells and what is their function

Answer 10

Specialized cells that remove excess water from the body

Question 11

What are ganglia and what do they do in flatworms?

Answer 11

A group of nerve cells that control the nervous system. They control its nervous system’s

Question 12

A group of cells that can detect changes in the amount of light in a faltworms envoirment is called an (a) ___________

Answer 12

Eyespot

Question 13

How do cilia help flatworms move and what do muscle cells allow them to do

Answer 13

Cilia on their epidermal cells help them glide through the water. Muscle cells controlled by the nervous system allow them to twist and turn so that they can react rapidly

Question 14

What is a hermaphrodite?

Answer 14

An individual that has both male and female reproductive organs

Question 15

What occurs during fission

Answer 15

And organism splits into two and each half grows new parts to become a new organism

Question 16

Is the following sentence true or false? Free living flat worms often have complex life cycles that involve both sexual and asexual reproduction

Answer 16

True

Question 17

What is true about turbellarians
A.) Most live in marine or fresh waters
B.) Most are the same color, form and size
C.) Most ade bottom dwellers
D.) The most familiar are planarians

Answer 17

A
C
D

Question 18

How does the blood fluke schistosoma Mansoni infect humans?

Answer 18

By burrowing into the skin

Question 19

In which host do blood flukes reproduce sexually and which do they reproduce asexually

Answer 19

They reproduce sexually in humans and asexually in snails

Question 20

In what areas is schistosomiasis particularly widespread?

Answer 20

In tropical areas that lack proper sewage systems, where human wastes are tossed into streams or used as fertilizer

Question 21

The head of a tapeworm is called a __________

Answer 21

Scolex

Question 22

What does a tapeworm use its Scolex for

Answer 22

To attach to the intestinal wall of its host where it absorbs nutrients

Question 23

Sperm is produced by male reproductive organs called _________

Answer 23

Testes

Question 24

Is the following sentence true or false? Sperm produced by a tapeworms testes can fertilize the eggs of the same individual

Answer 24

True