Tag: phylum hemichordata

Questions Related to phylum hemichordata

Which of the following is not a character of phylum Hemichordata?

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Presence of stomochord which is mesodermal in origin

  2. Excretory organ is proboscis gland

  3. Circulatory system is open

  4. Respiration takes place through gills

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Correct Option: A
Explanation:

Phylum Hemichordata consists of a small group of worm-like marine animals with an organ-system level of organisation. The body is cylindrical and is composed of an anterior proboscis, a collar, and a long trunk. The circulatory system is of open type. Respiration takes place through gills. The excretory organ is proboscis gland.

So the correct option is "Presence of stomochord which is mesodermal in origin".

Balanoglossus is connecting link between 

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Non- chordates and chordates

  2. Cartilaginous and bony fishes 

  3. Bony fishes and amphibians

  4. Amphibians and reptiles

Show answer
Correct Option: A
Explanation:

Connecting links are good evidences of organic evolution. These There are organisms exhibit intermediate characteristics of two taxonomic groups. Balanoglossus is a connecting link between non-chordates and chordates. Chimaera is a connecting link between cartilaginous and bony fishes. Coelocanth is a connecting link between bony fishes and amphibians. Sphenodon is a connecting link between amphibians and reptiles.

Thus, the correct answer is 'Non-chordates and chordates.'

In which of the following brain is absent?

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Cyclostomata

  2. Pisces

  3. Amphibia

  4. Protochordata

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Correct Option: D
Explanation:

Protochordates are closely related to vertebrates. These lack some of the peculiar characteristics of chordates like the true skull, brain, skeleton. These are invertebrates.

So, the correct answer is option D.

Which animal is non-chordate - protochordate?

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Botryllus

  2. Balanoglossus

  3. Branchiostoma

  4. All of the above

Show answer
Correct Option: B
Explanation:

Balanoglossus has some characteristics in common with chordates, such as gill slits and a dorsal nerve cord; however, this species also has a ventral nerve cord and the nerve cords in general are not hollow like most chordates, but instead are solid. Therefore they are nonchordate - protochordate. 

So, the correct answer is option B.

The feature that is not a characteristic of protochordata?

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Presence of notochord

  2. Bilateral symmetry and coelom

  3. Jointed legs

  4. Presence of circulatory system

Show answer
Correct Option: C
Explanation:
Jointed appendages are the characteristic feature of phylum Arthropoda which includes most of the insects.
Protochordate is an informal category of animals, named mainly for convenience to describe invertebrate animals that are closely related to vertebrates. This group is composed of the Phylum Hemichordata and the Subphyla Urochordata and Cephalochordata.
The Phylum Hemichordata consists of marine worms that share some, but not all of the characteristics of chordates. These animals have pharyngeal gill slits and a dorsal nerve cord, which is usually solid. The three body parts are proboscis, collar, and trunk. What was once thought to be a notochord is no longer considered homologous. Acorn worms are examples of hemichordates
The Urochordates and Cephalochordates are protochordate but belong to the Phylum Chordata
So, the correct answer is 'Jointed legs'

An animal which has notochord throughout its life is

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Fish

  2. Bird

  3. Snake

  4. Amphioxus

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Correct Option: D
Explanation:
The notochord is a cartilaginous structure which supports the body. It is formed by vacuolated cells. They are filled with fluid. These turgid cells will give strength to the notochord. This notochord is covered by a sheath of connective tissue. Amphioxus has notochord throughout its life. The notochord extends from the anterior end to the posterior end. It is placed below the dorsal nerve cord and above the alimentary canal. 
So, the correct answer is option D.

The body of acorn worms can be divided as

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Anterior proboscis

  2. Intermediate collar

  3. Posterior trunk

  4. All of the above

Show answer
Correct Option: D
Explanation:

Acorn worms is a hemichordate. They are closely related to echinoderms. They are solitary worm-shaped organisms. They can be traced in burrows and are deposit feeders, but some species are pharyngeal filter feeders.

The body of acorn worms is worm-shaped and divided into an anterior proboscis, an intermediate collar, and a posterior trunk. The proboscis is a muscular and ciliated organ used in locomotion and in the collection and transport of food particles. The mouth is located between the proboscis and the collar. The trunk is the longest part of the animal.
So, the correct answer is option D.

Hemichordata is considered as the sister group of

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Arthropoda

  2. Echinoderms

  3. Molluscs

  4. Both A and C

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Correct Option: B
Explanation:

Hemichordata is a phylum of marine deuterostome animals, generally considered the sister group of the echinoderms. They appear in the lower or middle Cambrian and include two main classes: Enteropneusta (acorn worms), and Pterobranchia. 

So, the correct answer is option B.

Coelom of hemichordates is

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Schizocoel

  2. Enterocoel

  3. Enterocoel with differentiation of three regions

  4. Absent

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Correct Option: C
Explanation:

A) Schizocoel is a type of coelom which is derived by splitting of mesoderm. It is not present in hemichordates.

B) Enterocoel is derived out of gastric pouches during embryonic development.
C) Enterocoel is present in hemichordates and their body is differentiated into three regions- proboscis, collar and trunk.
D) Hemichordates are enterocoelomates and coelom is not absent in them.
Since option c is a more complete answer,  the correct answer is option C.

Pharyngeal gill slits are dorsal in

zoology diversity in living world hemichordata phylum hemichordata chordates and hemichordates

  1. Cephalochordates

  2. Urochordates

  3. Hemichordates

  4. Euchordates

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Correct Option: C