Cnidarians

Question 1

What is the defining characteristic of Phylum Cnidaria?

Answer 1

The presence of cnidocytes, specialized cells that contain stinging structures called nematocysts.

Question 2

Which body forms are primarily associated with Cnidarians?

Answer 2

The polyp and medusa body forms.

Question 3

True or False: Cnidarians are primarily freshwater organisms.

Answer 3

False. Cnidarians are primarily marine organisms.

Question 4

What are the four main classes of Phylum Cnidaria?

Answer 4

Hydrozoa, Scyphozoa, Anthozoa, and Cubozoa.

Question 5

Fill in the blank: The class _______ includes jellyfish.

Answer 5

Scyphozoa

Question 6

What type of symmetry do Cnidarians exhibit?

Answer 6

Radial symmetry.

Question 7

True or False: Cnidarians have a true nervous system.

Answer 7

False. They have a simple nerve net.

Question 8

What is the primary method of reproduction in Scyphozoa?

Answer 8

Both sexual and asexual reproduction.

Question 9

In Cnidarians, what is the function of the gastrovascular cavity?

Answer 9

It serves as both a digestive and circulatory system.

Question 10

What is the larval stage of Scyphozoa called?

Answer 10

Planula.

Question 11

Which class of Cnidaria is known for its box-shaped medusa?

Answer 11

Cubozoa.

Question 12

True or False: All Cnidarians have a polyp stage.

Answer 12

False. Some, like jellyfish, primarily exist in the medusa stage.

Question 13

What structure do Cnidarians use for locomotion?

Answer 13

Muscular contractions of the body.

Question 14

Fill in the blank: The _______ stage of Scyphozoa develops from the planula.

Answer 14

Scyphistoma

Question 15

What is the process by which Scyphozoa reproduce asexually?

Answer 15

Budding.

Question 16

Which class includes sea anemones and corals?

Answer 16

Anthozoa.

Question 17

What is the ecological role of Cnidarians in marine ecosystems?

Answer 17

They are important as predators and as part of coral reef systems.

Question 18

True or False: Cnidarians have specialized tissues.

Answer 18

True.

Question 19

What is the primary feeding mechanism of Cnidarians?

Answer 19

They use tentacles to capture prey and bring it to the mouth.

Question 20

Fill in the blank: The _______ is the protective outer layer of Cnidarian bodies.

Answer 20

Epidermis

Question 21

What type of reproduction involves the exchange of gametes in Cnidarians?

Answer 21

Sexual reproduction.

Question 22

In Scyphozoa, what is the term for the young medusa that buds off from the scyphistoma?

Answer 22

Ephyra.

Question 23

Which class of Cnidaria is known for its potent venom?

Answer 23

Cubozoa.

Question 24

True or False: Cnidarians can regenerate lost body parts.

Answer 24

True.

Question 25

What is the role of nematocysts in Cnidarians?

Answer 25

They are used for capturing prey and defense.

Question 26

Fill in the blank: The _______ stage is generally the dominant phase in Scyphozoa.

Answer 26

Medusa

Question 27

How do Cnidarians primarily exchange gases?

Answer 27

Through diffusion across their body surface.

Question 28

Which Cnidarian class is primarily colonial?

Answer 28

Hydrozoa.

Question 29

What is the main advantage of having a radial symmetry for Cnidarians?

Answer 29

It allows them to interact with the environment from all sides.

Question 30

Fill in the blank: Cnidarians have a simple body plan that lacks _______.

Answer 30

Organs

Question 31

What is the primary habitat of Cnidarians?

Answer 31

Marine environments, though some inhabit freshwater.

Question 32

True or False: Cnidarians are considered to be the most primitive multicellular animals.

Answer 32

True.

Question 33

2 uses of tentacles/nematocysts

Answer 33

Feeding and defence

Question 34

State the arrangement of tentacles, cnidocysts and nematocysts

Answer 34

Nematocysts are in cnidocysts which are in tentacles

Question 35

Chemical toxins, which paralyse prey injected by cnidaria, are called

Answer 35

Darts

Question 36

Use of gastrovascular cavity

Answer 36

Digestion

Question 37

Type of digestion

Answer 37

Incomplete having only 1 opening that serves as mouth and anus

Question 38

Forms of reproduction

Answer 38

Asexual Sexual

Question 39

Cnidarians are Monocious or dioecious

Answer 39

Dioecious

Question 40

External fertilisation occurs to form a cbidarian larva. The larva is termed

Answer 40

Planula larva

Question 41

Asexual reproduced is done by

Answer 41

Budding

Question 42

Under anthozoa, which subclass does hard coral belong to

Answer 42

Hexacorallaria/zoantheria Have 6 fold symmetry

Question 43

Under anthozoa, which subclass does soft coral belong to

Answer 43

Octocorallia/ Alcyonacea - have 8 fold symmetry

Question 44

Does Hydra have a medusa stage?

Answer 44

No

Question 45

Morphism of obelia - mono/di/ tri morphic?

Answer 45

Obelia is colonial and Trimorphic

Question 46

Example of schyphozoa

Answer 46

Aurelia

Question 47

Fertilization is scyphozoa is - internal/external?

Answer 47

Internal