Sponges And Cnidaria

Front 1

Which type of symmetry has body parts arranged around a central axis?

Back 1

Radial symmetry is when parts are arranged around a central axis.

Front 2

What is symmetry?

Back 2

Symmetry refers to how body parts are arranged on an organism; patterns of arrangement.

Front 3

What is bilateral symmetry?

Back 3

Bilateral symmetry is when body parts are arranged in pairs on each side of a central axis.

Front 4

Define the term coelom.

Back 4

A coelom is a body cavity.

Front 5

Name the 3 germ layers and what each layer gives rise to.

Back 5

The ectoderm is the outer layer which gives rise to the skin, nerves, and sense organs. The
mesoderm is the middle layer that gives rise to the circulatory system, reproductive system, and
muscles. The endoderm is the inner layer which gives rise to the digestive system and respiratory
system.

Front 6

What is an acoelomate animal? Name an example of an acoelomate.

Back 6

An acoelomate animal is one in which there is no body cavity (coelom), it is solid. An example
would be a flatworm.

Front 7

Define the terms anterior, posterior, dorsal, and ventral.

Back 7

Anterior is the front end, posterior is the back end, dorsal refers to the top or back, and ventral
refers to the underside or belly area.

Front 8

In sponges, what two things form their support structure (skeleton)?

Back 8

Spongin and spicules make up the support system of a sponge.

Front 9

How do sponges get their food?

Back 9

Sponges are filter feeders, which means they create water current and trap food particles in the
water with their collar cells (choanocytes).

Front 10

What is the name of the large opening at the top of the sponge?

Back 10

The osculum is the large opening at the top of the sponge through which water leaves the sponge.

Front 11

Which cells line the interior of the sponge and create water currents by beating their flagella?

Back 11

The collar cells (choanocytes) line the interior of the sponge and create water currents by beating
their flagella.

Front 12

Which cells of a sponge move throughout the body wall of a sponge and distribute
nutrients?

Back 12

The amebocytes move throughout the sponge carrying out different functions.

Front 13

What does the term hermaphrodite mean?

Back 13

Hermaphrodites have the ability to produce both eggs and sperm.

Front 14

What is regeneration?

Back 14

Regeneration is the regrowing of lost body parts.

Front 15

How do sponges reproduce asexually?

Back 15

Sponges reproduce asexually through the formation of gemmules, regeneration, and budding.

Front 16

Name some examples of the Phylum Cnidaria.

Back 16

Some members of the phylum Cnidaria include jellyfish, coral, hydra, and sea anemones.

Front 17

Why was the phylum given the name Cnidaria?

Back 17

It was given the name to refer to the stinging cells they contain (the stinging cells are called
cnidocytes). The prefix cnido- means stinging.

Front 18

Name the two distinct life stages in many cnidarians.

Back 18

The two distinct life stages are the polyp and medusa.

Front 19

Define the term sessile.

Back 19

The term sessile means firmly attached to the bottom. Sessile animals do not move.

Front 20

What are anthozoans?

Back 20

Anthozoans are cnidarians such as sea anemones. They have an elongated body with tentacles
around the top. The name anthozoa literally means, “flower animal”.

Front 21

Which class of cnidarians contains the common jellyfish?

Back 21

The jellyfish are in the class Scyphozoa.

Front 22

What are nematocysts? Name 3 ways in which they work.

Back 22

Nematocysts are the stinging cells characteristic of all cnidarians. They work by paralyzing,
poisoning, or entangling their prey.

Front 23

What two compounds are spicules made of?

Back 23

Spicules are made up of calcium carbonate or silicon dioxide.

Front 24

What is a gemmule?

Back 24

A gemmule is a food-filled ball of amebocytes produced by sponges to survive harsh conditions; a
form of asexual reproduction in sponges.

Front 25

Which of the two phyla we have discussed in this unit contains all of the corals?

Back 25

Corals are in the phylum Cnidaria

Front 26

What level of organization do sponges have?

Back 26

Sponges have the cellular level of organization.

Front 27

What level of organization do cnidarians have?

Back 27

Cnidarians have the tissue level of organization.

Front 28

Where do most sponges live (what habitat)?

Back 28

Most sponges live in a marine environment. Only 150 species of the 10,000 species are freshwater.

Front 29

What are ostia?

Back 29

Ostia are the openings in the side of the sponge through which water enters the sponge.

Front 30

What is the hollow interior cavity of the sponge called?

Back 30

The hollow interior of the sponge is called the spongocoel.