Tag: characteristics of vertebrates

Questions Related to characteristics of vertebrates

Petromyzon cannot be called as fish, as

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

  1. It lacks median fins

  2. It lacks paired fins

  3. It lacks an operculum

  4. It has acicular mouth

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Correct Option: B
Explanation:
Petromyzon is the scientific name of the sea lamprey. It is long and slender snake like organism. This organism is not called as the true fish. The organism lacks the paired fins. The organism have well developed dorsal and ventral finfolds. This finfolds helps in swimming and locomotion. 
Thus, the correct answer is option B.

In which one of the following jaws are absent?

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

  1. Petromyzon

  2. Hagfish

  3. Hippocampus

  4. Both A and B

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Correct Option: D
Explanation:

Petromyzon is the sea lamprey, which lacks bony teeth and jaws. Hagfish is eel-shaped, slime-producing marine fish. Along with lampreys, they are jawless and are living fossils.

So, the correct answer is option D.

The lamprey is included in same taxonomic class as 

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

  1. Anolis 

  2. Myxine 

  3. Ambystoma

  4. Neoceratodus 

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Correct Option: B
Explanation:

Lamprey and hagfish or Petromyzon and Myxine are both agnathans as they are jawless fishes. They are sometimes considered as the earliest vertebrates. They also lack paired fins or stomach. They have a pineal eye. The adults and larvae usually have a notochord.

So, the correct answer is 'Myxine '.

Earliest jawed vertebrates were

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

  1. Ostracoderms

  2. Placoderms

  3. Crossopterygians

  4. Elasmobranchs

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Correct Option: B
Explanation:

Vertebrates are the subphylum of a Chordata. Placoderms were among the first jawed fish. The jaws are considered to evolve from the gill arches. Placoderms are the extinct class of armoured prehistoric fishes, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked.

So, the correct answer is option B.

Kidney of fish is of type ......................

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

  1. Pronephros

  2. Opisthonephros

  3. Metanephros

  4. Nephridia

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Correct Option: B
Explanation:

Cyclostomes are the organisms which belong to the group of chordates. These are the jawless fishes. The group also includes the lampreys and hagfishes. They have rounded mouths that lack jaws. The water keeps on cycling through the open mouth which cannot be closed due to lack of jaws. 

The opisthonephros is the kidney present in adults of these organisms. It is formed from the extended mesonephros along with the tubules from the posterior nephric ridge. 
Thus, the correct answer is option B.

Lamprey (Petromyzon) is included in 

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

  1. Gnathostomata.

  2. Cyclostomata.

  3. Chondrichthyes.

  4. Osteichthyes.

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Correct Option: B
Explanation:
Lampreys are one of the jawless fishes of the order Petromyzontiformes. Petromyzon is the scientific name of the sea lamprey. Chordates are characterized by the presence of notochord. Cyclostomata is a type of Chordate, that comprises the living jawless fishes, like the lampreys and hagfishes. It is long and slender snake-like organism. This organism is not called as the true fish. The organism lacks the paired fins. The organism has well developed dorsal and ventral fin folds. These fin folds help in swimming and locomotion. The adult stage is characterized by a toothed, funnel-like sucking mouth.
Thus, the correct answer is option B.

True fish possess gills and fins. Which one of the following is not a true fish?

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

  1. Carassius

  2. Hythalamincthyes

  3. Hippocampus

  4. Lepisma

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Correct Option: D
Explanation:

Carassius is a genus in the ray-finned fish family Cyprinidae.
Hippocampus is the name of marine fishes in the genus Hippocampus.
While Lepisma is a genus of primitive insects.
So, the correct answer is option D.

Which of the following is a jawless fish?

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

  1. Hippocampus

  2. Torpedo

  3. Petromyzon

  4. Mystus

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Correct Option: C
Explanation:

The hippocampus is the name of marine fishes.
Torpedo is the group of flattened cartilaginous fishes, also called an electric ray.
Mystus is a genus of small to medium-sized bagrid catfishes.
Petromyzon is the 'sea lamprey', which is parasitic lamprey. It is a 'jawless' fish.

So, the correct answer is option C.

Which strucutres is seen cyclostomes?

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

  1. Pineal eye

  2. Jaws

  3. Pectoral fin

  4. All of the above

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Correct Option: A
Explanation:

In cyclostomes, the pineal gland is a photoreceptor. The endocrine nature of the gland's function has not been definitely established. As it's activity diminishes with age, the gland turns into rudimentary organ containing mineral deposits.

So, the correct answer is option A.

The single median nostril is characteristic of 

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

  1. Birds

  2. Cyclostomes

  3. Bony fishes

  4. Protochordates

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Correct Option: B
Explanation:

Cyclostomes are animals with a circular mouth, eel-shaped body with jaw less mouth, single median nostril and no paired fins. So, the correct answer is option B.