In case of poriferans, the spongocoel is lined with flagellated cells called

An important characteristic that hemichordates share with chordates is

Which among these is correct combination of aquatic mammals

Which of the following characteristic features always holds true for the corresponding group of animals
$\begin{array}{cccc}\text{(a)}& \text{Cartilagious endoskeleton}& & \text{Chondrichthyes}\\ \text{(b)}& \text{Vivparous}& & \text{Mammalia}\\ \text{(c)}& \text{Possess a mouth with an upper and a lower jaw}& & \text{Chordata}\\ \text{(d)}& \text{3- chambered heart with one incompletely divided ventricle}& & \text{Reptilia}\end{array}$

Which of the following features is not present in the in the phylum arthropoda

Metagenesis referes to

Choose the correct statement.

A jawless fish which lays eggs in fresh water and whose ammocoete larve after metamorphosis return to ocean is

Which of the following characteristics is not shared by birds and mammals

One of the representative of Phylum arthropoda is