Biology Ch. 26-28 Worms and Mollusks Quiz(AT) Flashcards
Flatworms are the simplest animals that have what five things?
- They have soft, flattened bodies.
- They have tissues and internal organ systems.
- As embryos, they have three germ layers.
- They have bilateral symmetry.
- They show cephalization. (They have a ‘head’.)
Why are flatworms called acoelomates?
They do not have a true coelom. Their only body cavity is the digestive cavity.
_______ is a fluid filled body cavity derived from the mesoderm.
Coelom
How is the digestive process different in free-living flat worms compared to parasitic flatworms?
Free-living flat worms can be carnivores or scavengers while parasitic flatworms must have a host.
Name the biological systems that take advantage of diffusion in flatworms.
Respiration, circulation, digestion, and excretion.
_______ is a specialized cell used to eliminate excess water and wastes from free-living flatworms.
Flame cell
_______ is a group of nerve cells that control the nervous system in free-living flatworms.
Ganglia
______ is a group of cells that detect light changes.
Eyespot
What are two ways flatworms move?
Cilia and muscles (twist and turn)
How does reproduction differ between free-living flatworms and parasitic flat worms?
Free-living flatworms do not need a host to reproduce.
_________ is the only group of free-living flatworms.
Turbullerians
_______ mostly infect internal organs of host organisms but they can also infect the skin, mouth, gills, etc.
Flukes
_________ are typically the longer worms found in the host’s intestine.
Tapeworms
________ contains suckers and hooks to attach to the host’s intestinal wall.
Scolex
________ are segments that make up most of the body and contain both the male and female reproductive organs.
Proglottids
Describe what a round worm looks like?
Slender and non-segmented
Where are they found?
Infected meat, water, and soil
In round worms, food passage is in _________ direction.
one
Roundworms depend on _________ to carry nutrients and wastes through their bodies.
diffusion
What does their nervous system consist of?
Ganglia