Lab 3: Phylum Cnidaria

Question 1

What are cnidaria?

Answer 1

Soft-bodied stinging animals such as corals, sea anemones, and jelly fish

Question 2

What clade do cnidarians belong to?

Answer 2

Eumetazoa, like other animals, because they form tissues

Question 3

The highest level of organization of sponges is?

Answer 3

Cells

Question 4

Type of symmetry found in sponges?

Answer 4

Assymetrical

Question 5

The highest level of organization of cnidarians is?

Answer 5

Tissues

Question 6

The type of symmetry found in cnidarians is?

Answer 6

Radial symmetry

Question 7

What is the name of the tissue found in the inner layer of the body wall of an adult anemone?

Answer 7

Gastrodermis

Question 8

From what germ layer of the embryo did this gastrodermis tissue layer develop?

Answer 8

Endoderm

Question 9

What is the name of the middle layer of an adult anemone?

Answer 9

Mesoglea

Question 10

Which is true about the middle layer of an adullt anemone?

Answer 10

It is composed of non-living gel-like material.

Question 11

During what stage of development do the germ layers form?

Answer 11

Gastrulation

Question 12

Which change of shape will contraction of the circular muscles produce?

Answer 12

Taller and Thinner

Question 13

Antagonistic muscles are necessary because…

Answer 13

Muscle can only shorten. An antagonist is needed to return them to their original shape.

Question 14

What property of water makes it useful as part of a hydrostatic skeleton?

Answer 14

When pressure is applied to a water filled space, it can not be compressed but can transfer the pressure to another part of the body.

Question 15

What is the name of an anemone’s feeding strategy?

Answer 15

Suspension Feeding

Question 16

T/F: Excess carbohydrates are converted into nitrogenous waste.

Answer 16

False

Question 17

What is the name of the nitrogenous waste in cnidarians?

Answer 17

ammonia

Question 18

Nitrogenous waste must be excreted from the body. How do cnidarians get nitrogenous waste out of their body?

Answer 18

It diffuses out of each individual cell into the surrounding water.

Question 19

Which of the following happens to the zooxanthellae and coral relationship when the temperature of the surrounding water becomes too hot?

Answer 19

The zooxanthellae are expelled from the coral.

Question 20

How does the appearance of coral change when the temperature of the surrounding water becomes too hot?

Answer 20

The coral appear white.

Question 21

What is a Polyp?

Answer 21

a cycliner-like body with the mouth pointing up and tentacles waving above. Ex. Anemone

Question 22

What is a medusa?

Answer 22

A bell-shaped body with the mouth pointing down and the tentacles hanging below. Ex. Jelly fish

Question 23

What is the internal space in an adult anemone?

Answer 23

The gastrovascular cavity

Question 24

What type of nervous system do cnidarians have?

Answer 24

A diffuse, non-centralized nervous system. They lack a true brain and instead have a system of separate , individual neurons located throughout the body

Question 25

What are the requirements of a hydrostatic skeleton?

Answer 25

1. an enclosed cavity containing a substance (usually water) that cannot be compressed 2. the volume of a liquid in the cavity should remain constant while pressure is being applied, therefore the compartment must remain closed 3) the cavity is located between a set of muscles that must act opposite to one another; these are called antagonistic muscles 4) nerve cells to stimulate the muscles to contract (shorten) 5) the cavity must be surrounded by a flexible outer body membrane so that the outer body wall can be deformed (shape changed)

Question 26

What is a nematocyst?

Answer 26

A barbed, venomous, coiled thread-like structure within the cells of the body wall in a cnidarian

Question 27

Where do coral get their color from?

Answer 27

Tiny algae inside of them called zooxanthellae. Ex. mustualistic symbiotic relationship

Question 28

What germ layer of the embryo did the Epidermis come from?

Answer 28

Ectoderm

Question 29

What layer is the epidermis?

Answer 29

Outer

Question 30

Does an anemone have a complete or incomplete digestive tract?

Answer 30

Incomplete

Question 31

What part of an anemone secretes digestive enzymes?

Answer 31

Gastrodermis

Question 32

What part of an anemone distributes nutrients?

Answer 32

GVC

Question 33

Jellyfish can be larger because their bells are packed with mesoglea. Why does this solve the surface area to volume dilemma?

Answer 33

Because jellyfish mesoglea isn't living so it can get thick and not need O2 while animals with a living middle layer need to be flat so every living layer gets O2