Sponges and Cnidaria and Cnetophora

Question 1

What Phylum are sponges a part of?

Answer 1

Porifera meaning “pore bearers”

Question 2

Do sponges have true tissues?

Answer 2

No. They have no nervous system or muscles. They have a loose aggregation of cells.

Question 3

What environments do sponges live in?

Answer 3

Mostly marine and all aquatic

Question 4

How do Sponges feed?

Answer 4

Filter feed through many pores and canals

Question 5

What cells pump water in sponges?

Answer 5

Collar Cells (Choanocytes) pump water

Question 6

What is the sponge made of?

Answer 6

Skeleton made of spicules and spongin

Question 7

Do sponges move?

Answer 7

No. They are sessile but have motile larvae.

Question 8

How has the sponge body plan evolved over time?

Answer 8

To enhance filtration efficiency with a high internal surface area with lots of canals and chambers.

Question 9

What is the name of the opening where water flows in through on the sponge?

Answer 9

Ostium

Question 10

What feature defines the Phylum Porifera?

Answer 10

Collar Cells (Choanocytes)
-They pump water and allow for particle feeding

Question 11

How do Choanocytes work?

Answer 11

Flagellum in choanocyte beats back and forth causing pressure gradient

• water is sucked in through collar of microvilli
• particles are caught and eaten as they pass through the collar

Question 12

What are Archaeocytes?

Answer 12

Ameoboid cells that live in the mesohyl

• They ingest, digest food caught by choanocyte collars (intracellular digestion)
• They are totipotent (can change into any sponge cell)

Question 13

What is the mesohyl in the sponge?

Answer 13

Gelatinous extracellular matrix made of jelly like collagen

Question 14

What is the major structural protein in Metazoa (including sponges)?

Answer 14

Collagen

Question 15

How do sponges reproduce?

Answer 15

Sexual Reproduction
-Releasing sperm and creating eggs (hermaphroditic)

Asexual Reproduction
-Budding and/or Fragmentation

Question 16

What else live in the cells or mesohyl of the sponge?

Answer 16

Symbiotic microbes that help produce unique organic compounds

Question 17

What can the unique organic compounds produced by sponges/microbes be used for?

Answer 17

new sources of medicines

Question 18

How do sponges accomplish Excretion/Respiration?

Answer 18

Diffusion

Question 19

Do Sponges have germ layers, symmetry or are they protostomes or Deuterostomes?

Answer 19

No Germ Layers
No Symmetry
Not a protostome or deuterostome

Question 20

What is the group Radiata and what Phyla are included in this group?

Answer 20

Radiata are the two phyla with radial symmetry

-Includes Phyla Cnidaria and Cnetophora

Question 21

What kinds of tissues do Radiata have?

Answer 21

2 Germ Layers
-Endoderm and Ectoderm

No Mesoderm or organ systems

Question 22

Do Radiata have a stomach?

Answer 22

No. They have a Gastrovascular Cavity (gut)

Question 23

What environments do Radiata live?

Answer 23

Mostly Marine all aquatic. Some freshwater.

Question 24

What species are included in Phylum Cnidaria?

Answer 24

Jellyfish, Anemones, and Corals

Question 25

What is the defining characteristic of Phylum Cnidaria?

Answer 25

Presence of Cnidocytes

Question 26

Do Phylum Cnidaria species move?

Answer 26

Some are Sessile (Corals) and some are Moblie (Jellyfish) | -The ones that are mobile don't swim, they drift

Question 27

Are Cnidaria diploblastic or triploblastic?

Answer 27

Diploblastic b/c they have 2 germ layers

Question 28

How do Cnidaria reproduce?

Answer 28

Sexually and Asexually

Question 29

What are the two bodyplans of Cnidaria?

Answer 29

Polyps and Medusae

Question 30

What are the Classes under Phylum Cnidaria?

Answer 30

Cubozoa, Scyphozoa, Anthozoa, Hydrozoa

Question 31

Describe the Phylum Cnidaria body plan.

Answer 31

Polyp - sessile, thin mesoglea Medusa - free swimming, mobile Mesoglea - jellylike layer thicker in medusa (acts as skelton)

Question 32

How many openings are there to the gastrovascular cavity in Phylum Cnidaria?

Answer 32

THere is one opening (mouth) and the gastrovascular cavity somtimes acts as a skeleton

Question 33

Where are the highest concentration of cnidocytes?

Answer 33

The tentacles

Question 34

What are Cnidocytes?

Answer 34

Specialized epithelial cells that secrete the Cnide (Nematocyst) - Nematocyst pressurized to 2000 psi - May release toxins or digestive enzymes

Question 35

What is the stimuli for discharge of the Cnide (nematocyst)?

Answer 35

The Cnidocil is disturbed or mechanoreceptor cells or chemoreceptor cells

Question 36

What happens to the Cnidocyte after the Cnide (nemtocyst) is fired?

Answer 36

The Cnide is used up but the Cnidocyte isn't. It will reproduce another nematocyst.

Question 37

Where do epithelio muscular cells derive from in the Cnidaria since there is no mesoderm?

Answer 37

Derived from ectoderm

Question 38

Why doesn't water pass between cells in the Phylum Cnidaria?

Answer 38

The epidermis and gastrodermis are both epithilia with gap junctions that form a seal

Question 39

Explain the reproduction and life histories of Phylum Cnidaria, Class Hydrozoa.

Answer 39

1. Polyps for most of life - Sexual reproduction occurs during medusa stage - Makes Larva - Larva uses asexual reproduction to build colony of polyps - the polyps have gastrozooids to feed - the polyps have gonozooids which sprout the medusa stage of the life history

Question 40

Explain the reproduction and life histories of Phylum Cnidaria, Class Scyphozoa.

Answer 40

1. Jellyfish for most of life - female medusa egg is fertilized (sexual reproduction) - the zygote develops into planula larva - larva implants on surface and grows (polyp stage) - eventually produce the ephyra (asexual reproduction) which grows into medusa stage

Question 41

What species are included in Class Cubozoa?

Answer 41

box jellyfish and sea wasp

Question 42

What species are included in class anthozoa? WHat are the features?

Answer 42

anemones and coral - no medusa stage only polyp - symbiosis with dinoflagellate, zooxanthellae allow corals to form reefs

Question 43

Are Cnidaria protostomes or deuterostomes?

Answer 43

Neither

Question 44

What is the skeletal system of Cnidaria?

Answer 44

mesoglea

Question 45

How do Cnidaria feed?

Answer 45

Carnivorous, using nematocysts

Question 46

How do Cnidaria accomplish excretion/respiration?

Answer 46

Diffusion

Question 47

What Species are included in Phylum Cnetophora?

Answer 47

Comb jellies and sea gooseberries

Question 48

What are the distinguishing characteristics of Cnetophores?

Answer 48

Cnetes or combs of 8 rows which move animal in the plankton - all aquatic, all marine - Colloblasts: sticky, snare prey (not cnidocytes)