An organism ‘X’ belongs to the class ‘Y’ in which the members are cold blooded,  body covered with dry scales, fertilization is internal and have three chambered heart.  But ‘X’ has all these features except for the number of chambers of heart.  It has four chambered heart.  Identity X  and Y.

Which is not a vertebrate character?

Select the oviparous vertebrates.

Which is not a feature of Echinodermata?

Match the features of eggs of these groups.

Select the features of external fertilization.

Organisms which successfully breed together and produce fertile offspring belongs to the: