Select the correct statements :
(A) Platyhelminthes are triploblastic pseudocoelomate and bilaterally symmetrical organisms.
(B) Ctenophores reproduce only sexually and fertilization is external.
(C) In tapeworm, fertilization is internal but sexes are not separate.
(D) Ctenophores are exclusively marine, diploblastic and bioluminescent organisms.
(E) In sponges, fertilization is external and development is direct.
Choose the correct answer from the options given below :
Radial symmetry is NOT found in adults of phylum ______.
Select the correct statements with reference to chordates.
A. Presence of a mid-dorsal, solid and double nerve cord.
B. Presence of closed circulatory system.
C. Presence of paired pharyngeal gill slits.
D. Presence of dorsal heart
E. Triploblastic pseudocoelomate animals.
Choose the correct answer from the options given below:
The unique mammalian characteristics are :