Worms, Cnidarians,and SpongesReview Sheet Answers

Sponges #1

What is an invertebrate?Invertebrates are animals that do not have backbones.

Sponges #2

What does asymmetrical mean?

It has no symmetry.

Sponges #3

Define sessile.An organism spends its life attached to one spot and does not move from place to place.

Sponges #4

What are pores? How do they help sponges?

Small openings that surround the entire body of a sponge. They allow water and oxygen to enter the sponge’s body.

Sponges #5

How do sponges obtain food and oxygen?

Water travels through the pores and it carries food and contains oxygen molecules. The specialized cells filter them out.

Sponges #6

Do sponges have tissues, cells, or organs?

CELLS!!

Sponges #7

What are spikes? How do they help sponges?

They form a rigid frame that helps support the sponge’s body. They also are a defense mechanism.

Sponges #8

Describe the two types of reproduction.

Asexually: Budding. Buds form on the parent sponge and eventually break off and float away.Sexually: Fertilization. Sperm are released by a male sponge and then fertilize a female’s eggs.

Sponges #9

What is a larva?A fertilized egg becomes a larva. It is the immature form of the adult and looks very different.

Cnidarians #10

What is radial symmetry?

Many lines of symmetry, all through a center point.

Cnidarians #11

How are cnidarians’ tentacles unique?

They have stinging cells.

Cnidarians #12

What is a nematocyst?A capsule in the stinging cell that holds a barbed filament.

Cnidarians #13

Cnidarians are more advanced than sponges because they have….

TISSUES!

Cnidarians # 14

Describe the two types of reproduction of cnidarians.

Asexual – Budding (buds form on the adult, break off, float away, and then attach to the ocean floor).Sexual – Sperm are carried to the egg where fertilization occurs.

Cnidarians # 15

What is a polyp?Vase-like shape.

Mouth is on the top.

Sessile

What is a medusa?Free swimming animal.

Mouth is on the bottom.

Looks like an upside down bowl.

Worms #1

What are the 3 types of worms?

Flatworms: they are FLATRoundworms: they are ROUNDSegmented worms: they have SEGMENTS

Worms #2

What is bilateral symmetry?

Only one line of symmetry in the animal.

Worms #3

What is regeneration?The ability to regrow body parts.

Worms #4

What is a parasite?Organism that lives on or in another organism.

Worms #5

What is an eyespot?Allow the organism to see light versus dark. Planaria have them.

Worms #6

What are odor cells?Allows the organism to smell food. Planaria have them.

Worms #7

How do planaria eat?They insert feeding tubes into the food.Next, digestive juices start to digest the food outside the worm.Finally, the feeding tubes bring the prey into the worm.

Worms #8

Where do most roundworms live?

Moist environments

Worms #9

What type of digestive tract do roundworms have?

Open at both ends or one way.

Worms #10

• What are segments?– Tiny linked sections that

cover the worm’s body.

Worms #11

• Describe the digestive tract of segmented worms.– Open @ both ends –

One Way.

Worms #12• Describe a closed circulatory

system. What is it and why do some animals have it?

•Blood moves through a connected network of blood vessels.

• It is important because it allows animals to grow larger.

Worms #13

• What does it mean that earthworms are scavengers?– They eat decayed plant

and animal remains in soil.

Worms #14

• Why do earthworms need moisture?– They get oxygen from the

water that’s on their skin. – No moisture = no oxygen.

Worms #15

• How do earthworms help gardeners and farmers?– Tunnels loosen soil and

provide room for air, water, and roots, which promote plant growth.