Features of Flatworms

Question 1

Flatworms have ____ digestive system.

Answer 1

Flatworms have an incomplete digestive system.

Question 2

This means that the digestive tract has ____ opening/s.

Answer 2

only one opening.

Question 3

Digestion takes place where

Answer 3

The gastrovascular cavity.

Question 4

Flatworms have no true body cavity, but they do have bilateral symmetry. Due to the lack of a body cavity, flatworms are known as _____

Answer 4

acoelomates

Question 5

Oxygen enters the pores by ____

Answer 5

diffusion

Question 6

Flatworms do not have a respiratory system. Instead, they have _____ that allow oxygen to enter through their body. Oxygen enters the pores by diffusion.

Answer 6

pores

Question 7

There are no _____ ______ in the flatworms.

Answer 7

blood vessels

Question 8

Their __________ _____ helps distribute nutrients throughout the body.

Answer 8

gastrovascular cavity

Question 9

Most flatworms have a distinct head region that includes nerve cells and sensory organs, such as _____

Answer 9

eyespots

Question 10

The development of a head region, called ________

Answer 10

cephalization

Question 11

The development of a head region, called cephalization, evolved at the same time as ______ symmetry in animals.

Answer 11

bilateral symmetry

Question 12

The development of a head region, called cephalization, evolved at the same time as bilateral symmetry in animals. This process does not occur in ______

Answer 12

cnidarians

Question 13

This process does not occur in cnidarians, which evolved prior to flatworms and have _____ symmetry.

Answer 13

radial symmetry