Tag: classifications of chordata

Questions Related to classifications of chordata

In which of the following animal only one single median nostril is present?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Salamander

  2. Petromyzon

  3. Labeo

  4. Rana

Show answer
Correct Option: B
Explanation:
Petromyzon or Lamprey is an example of jawless fish belonging to class- Cyclostomata. They have one nostril on the top of their head.
Salamander, Lobeo and Rana have 2 nostrils.
So, the correct option is 'Petromyzon'.

Which of the following is a circular mouthed fish?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Myxine

  2. Torpedo

  3. Trygon

  4. Scoliodon

Show answer
Correct Option: A
Explanation:

  • Cyclostomata is a group of jawless living fishes which belong to the superclass Agnatha.
  • Eg- the lampreys and hagfishes.
  • The name Cyclostomata means circular mouths.
A. Myxine is a genus of hagfish.
B. Torpedo is a flattened cartilaginous fish which is also known as electric fish.
C. Trygon is a cartilaginous fish which is also known as stingfish.
D, Scoliodon is cartilaginous fish which is also known as dogfish.
  • All the cartilaginous fishes belong to Gnathostomata i.e they have jaws.
  • So, the correct answer is 'Myxine'.

The notochord is present throughout the life in organisms belonging to which of the following group?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Agnatha

  2. Cephalochordata

  3. Urochordata

  4. Both A and B

Show answer
Correct Option: D
Explanation:

Cephalochordates are a group of organisms in which the notochord extends from head to tail region and is persistent throughout their life. Agnatha is a group of vertebrates that lacks jaw and notochord is present in both larvae and adult forms. While in Gnathostomata (jawed vertebrates) notochord is replaced by a vertebral column in adults.

In Urochordata, the notochord is present only in the larval tail. 
So, the correct option is 'Agnatha and Cephalochordata'.

What is the fate of notochord in an adult organism which belongs to Gnathostomata?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Notochord extincts

  2. Notochord is replaced by the vertebral column

  3. Notochord becomes vestigial

  4. Notochord continues same as in larval stage

Show answer
Correct Option: B
Explanation:

  • Phylum Chordata can be divided into two categories:-
1) Protochordata- The notochord is present in the larval stage of these animals and it is rudimentary in adults.
2) Vertebrata- The notochord is replaced by a vertebral column in adults.
  • Gnathostomata is a superclass which includes jawed vertebrate fishes.
  • They come under the subphylum vertebrata i.e the notochord is replaced by a vertebral column in adults.
  • So, the correct answer is 'Notochord is replaced by the vertebral column'.

In which of the following haemocyanin pigment is found?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Armada

  2. Echinodermata

  3. Insecta

  4. Lower invertebrates

Show answer
Correct Option: A

Which among the following is the lowest grade vertebrate?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Agnatha

  2. Cyclostomata

  3. Echinodermates

  4. Both A and B

Show answer
Correct Option: D
Explanation:

Agnatha is a superclass of jawless fishes in the phylum Chordata. These are ectothermic, meaning they do not regulate their own body temperature. They show slow metabolism in cold water. They do not have a proper stomach rather they have a long homogenous gut. They are lowest grade vertebrates. The notochord is persistent in them. 

Cyclostomata is a group of chordates that comprises the living jawless fishes - the lampreys and hagfishes. These fishes are a parasite as well as scavengers. The body is long, then tubular and tail is flat. They are also known as false fish.
So, the correct answer is option D.

Petromyzon is included under

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Cephalochordata

  2. Agnatha

  3. Tetrapoda

  4. Pisces

Show answer
Correct Option: B
Explanation:

The sea lamprey (Petromyzon marinus) is a parasitic lamprey found in the northern Atlantic Ocean along shores of Europe and North America, in the western Mediterranean sea and in the shores of the Great Lakes. It belongs to superclass Agnatha (It is a superclass of jawless fishes). It is brown, gray, or black on its back and white or gray on the underside. The lamprey uses its suction cup-like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp, probing tongue and keratinized teeth.

So, the correct answer is option B.

........... is a living fossil.

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Drepanaspis

  2. Lamprey

  3. Cephalaspis

  4. All of the above

Show answer
Correct Option: B
Explanation:

Petromyzen or Lamprey is a living fossil. The sea lamprey lacks bony teeth and jaws. It has an oral armament of conical teeth made of keratin. The lamprey even has teeth on its tongue. The oral apparatus of the adult lamprey is a sucking disk lined with whorls of over 100 of these teeth. 

So, the correct answer is option B.

Which among the following are known as false fishes?

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Pisces

  2. Cyclostomata

  3. Ostracodermi

  4. All of the above

Show answer
Correct Option: B
Explanation:

Cyclostomata is a group of chordates that comprises the living jawless fishes - the lampreys and hagfishes. These fishes are a parasite as well as scavengers. The body is long, then tubular and tail is flat. They are also known as false fish.

So, the correct answer is option B.

Toothed, funnel-like sucking mouth seen in

biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

  1. Lamprey

  2. Myxine

  3. Ostracodermi

  4. Hilsa

Show answer
Correct Option: A
Explanation:

Adult lamprey may be characterised by toothed, funnel like sucking mouth. The common name 'lamprey' is probably derived from latin, 'lampetro' which may mean stone licker.