Tag: cnidaria

Quizzes (3) Questions (48)

Questions Related to cnidaria

Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria

Ctenophora shows affinities with 

  1. Cnidaria

  2. Aschelminthes

  3. Cephalopoda

  4. Turbellaria
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ctenophora shows several affinities with Cnidaria, some of them are:

1. The radial and tetramerous symmetry of the body, like the medusa of the hydrozoans.
2. Arrangement of parts along oral-aboral axis. 
3. Presence of branching gastrovascular canals and absence of coelom.
4. Presence of tentacles and statocyst.
5. Endodermal nature of gonads etc.
Hence, option A is correct.

Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria

Which of the following phylum includes comb jelly?

  1. Mollusca

  2. Echinodermata

  3. Coelenterata

  4. Ctenophora
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Ctenophores, commonly known as sea walnuts or comb jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue level of organization. The germs layers include ectoderm and endoderm. 

So, the correct answer is option D.

Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria

Hydra recognizes its prey by

  1. Nematocyst

  2. Smell

  3. Sensitivity

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hydra traps its prey by  tentacles which are present at the opening of the gastrovascular cavity. Scattered over the outer layer tentacles are a great many of these stinging cells called cnidoblasts. Each cnidoblast contains a capsule (nematocyst) from which projects a small trigger called a cnidocil. Inside each capsule is a tiny hollow thread. It is inverted like a finger of a glove which is pushed into the hand part. These threads are the food-catching apparatus. 

So, the correct answer is option A.

Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria
 A. Symmetry of ctenophorans  1. Haeckelia
 B. Ctenophora with nematocyst  2. Radial
 C. Habitat of comb jellies   3. Colloblast
 D. Specialised cells of comb jellies  4. Marine


  1. A- 3, B- 4, C- 2, D- 1

  2. A- 4, B- 3, C- 2, D- 1

  3. A- 1, B- 2, C- 3, D- 4

  4. A- 2, B- 1, C- 4, D- 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
The ctenophores have radial symmetry. They have elongated and tubular body. They are attached to the substratum by on end. The other end has an opening called as mouth which is surrounded by long tentacles. Thus, the symmetry of these organism are called as biradial symmetry. 
Species of Haeckelia are known to carry nematocysts on their medusae. They carry the nematocysts on their tentacles. There are nematocysts which are arranged on the medusae. 
Habitat of comb jellies is marine waters. They can survive in shallow waters as well as in depth. Some of the species are found near the water surface.
Specialised cells are present in comb jellies which are known as colloblasts. These are sticky type of cells and adhere to the prey. This helps in capturing the prey as these organisms lack the stinging cells. 
Thus, the correct answer is option D. 
Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria

Why does the Ctenophora is a minor phylum?

  1. It includes small sized animals.

  2. It includes only few genera.

  3. It does not includes animals of economic importance.

  4. It was included earlier in Cnidaria.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ctenophora is considered as a small phylum. The phylum contains very few genera and only about 80 species. This group includes a set of marine animals. These organisms are commonly called as comb jellies. Earlier, this phylum was placed under Coelenterata. Hatschek placed it under a separate phylum. 

Thus, the correct answer is option B. 

Multiple choice zoology animal diversity - i (inverterbrate phyla) ctenophora phylum ctenophora cnidaria

Biradial symmetry and lack of cnidoblasts are the characteristic of 

  1. Hydra and starfish

  2. Starfish and sea anemone

  3. Ctenoplana and Beroe

  4. Aurelia and Paramoecium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Biradial symmetry and lack of cnidoblasts are characteristics of phylum Ctenophora. They have adhesive structure, known as coloblasts instead of cnidoblasts. Both Ctenoplana and Beroe are ctenophores. Hence, option C is correct.