Multiple Choice QuestionsChondrichthyes is characterised by
Placoid scale
Ventral mouth
Ctenoid scale and ventral mouth
Placoid scale and ventral mouth
D.
Placoid scale and ventral mouth
Chondrichthyes is one of the classes of super-class-Pisces, sub-phylum-Vertebrata and phylum Chordata. The members of class-Chondrichthyes are marine animals with a streamlined body and have a cartilaginous endoskeleton. Mouth is located ventrally. The skin is tough, containing minute placoid scales. The teeth are modified placoid scales which are backwardly directed, e.g., Dog fish (Scoliodon), sawfish (Pristis), great white shark (Carcharodorus sting ray (Trygon), etc.
Animals of class-Mammalia have
Seven cervical vertebrae
Seven cranial nerve
Single ventricular chamber
Fourteen cervical vertebrae
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