Tag: diversity in living world

Questions Related to diversity in living world

Which of the following is present at the anterior end of Balanoglossus?

  1. Proboscis

  2. Collar

  3. Hepatic region

  4. Brachiocephalic region


Correct Option: A
Explanation:
In longitudinal section of the anterior region of Balanoglossus, three parts are visible i.e., proboscis, collar, and trunk. Among these, the proboscis is present in the anterior end. It is almost round in shape. Proboscis helps in burrowing through the sand. 
So, the correct answer is 'Proboscis'.

Tongue worm is 

  1. Nereis

  2. Taenia

  3. Balanoglossus

  4. Ancyclostoma


Correct Option: C
Explanation:

Any wormlike invertebrate of the phylum Pentastomida (or subphylum of Arthropoda), having two pairs of hooks at the sides of the mouth: all are parasitic, some in the respiratory tracts of mammals.

Nereis is a genus of polychaete worm.
Taenia is a tapeworm.
Balanoglossus is the acorn worm. It is also called Tongue worm due to the resemblance of the proboscis & genital wings to Ox tongue.
Ancyclostoma It is a parasitic nematode worm
So the answer is 'Balanoglossus'. 

Notochord is absent in the group

  1. Hemichordata

  2. Chordata

  3. Cephalochordata

  4. Urochordata


Correct Option: A
Explanation:

Hemichordates are marine invertebrates which are closely related to both chordates and echinoderms. They are deuterostomes which have pharyngeal gill slits and most of them have a dorsal nerve cord and they lack a notochord.

So, the correct answer is 'Hemichordata'.

A chordate having both vertebral column and notochord in adult stage is?

  1. Branchiostoma

  2. Rattus

  3. Scoliodon

  4. Bungarus


Correct Option: A
Explanation:
(A) Branchiostoma
Branchiostoma is one of the few living genera of lancelets. A chordata having both vertebral column and notochord in adult stage is Branchiostoma.

Choose the incorrect statement.

  1. Balanoglossus is a worm like marine animal with external fertilization and indirect development

  2. Urochordates exhibit retrograde metamorphosis

  3. Crocodiles have completely divided for chambered heart

  4. Male Macropus is a mammal exhibiting saltatory locomotion and brood pouch for parental care


Correct Option: A

Hemichordates are the connecting link between

  1. Urochordates and cephalochordates

  2. Cephalochordates and vertebrates

  3. Urochordates and vertebrates

  4. Non-chordates and chordates


Correct Option: D
Explanation:

Hemichordates means half chordates. It is a connecting link between non-chordates and chordates as they share some characteristics of both. The chordates have creatine in their energy cycle for the muscle contaction while non-chordates have arginine but the hemichordates have both i.e., creatine as well as arginine.

So, the correct answer is option D.

Which one of the following is not true for protochordates?

  1. Presence of dorsal nerve cord

  2. Tail behind the anal opening

  3. Presence of gill slits

  4. Presence of segmented body


Correct Option: D
Explanation:
Protochordates are characterized by the presence of dorsal nerve cord, tail behind the anal opening, presence of gill slits.
The segmented body is mainly seen in annelids and arthropods amongst the invertebrates.
So, the correct answer is option D.

The feature that is not a characteristics of protochordata?

  1. Presence of notochord

  2. Bilateral symmetry and coelom

  3. Jointed legs

  4. Presence of closed circulatory system

  5. Both C and D


Correct Option: E
Explanation:

Protochordates are the animals having a dorsal hollow nerve cord, pharyngeal gill slits, and a notochord. They are usually referred to as the oldest chordates. They mainly include tunicates and cephalochordates. They are bilaterally symmetrical and possess a coelom. They do not have a closed circulatory system or jointed legs.

So, the correct answer is 'Both C  and D'.

Which of these is not an example of protochordata ?

  1. Balanoglossus

  2. Herdemania

  3. Amphioxus

  4. Asterias


Correct Option: D
Explanation:

Asterias ( star fish) is an example of echinodermata and not protochordata as they have a hard calcium carbonate structure that it uses as their skeleton.

Which of the following list contains only hemichordates?

  1. Earthworm

  2. Acorn worm

  3. Hydra

  4. Liverfluke


Correct Option: B
Explanation:

Earthworm is an annelid, hydra is a coelenterate, liverfluke is a platyhelminthes, acorn worm (Balanoglossus, Saccoglossus) is a hemichordate belonging to class Enteropneusta.