question_answer 50)

Match the following and write correct choice in space provided

Animal	Characteristics
A. Pila	(i) Jointed appendages
B. Cockroach	(ii) Perching
C. Asterias	(iii) Water vascular system
D. Torpedo	(iv) Electric organ
E. Parrot	(v) Presence of shell
F. Dog fish	(vi) Placoid scales

A. ...................              B. ................... C. ...................               D. ................... E. ...................               F. ...................

Answer:

  A. (v)    B.  (ii)   C.  (iii)    D.  (iv)    E. (ii)    F.  (vi) a. Pila-Presence of shell Shell in Pila is an elongated structure which consists of a tubular whorl coiled around a central axis called columella. The main function of shell is to provide protection from harsh conditions. b. Cockroach-Jointed appendages Presence of jointed appendages along with segmented body is the characteristic feature of arthropods (e.g., spiders, bees, crabs etc). c. Asterias-Water vascular system It is the unique and characteristic feature in echinoderms. This system acts as a hydraulic system, composed of canals connecting numerous tube feet. It is very important as it helps Asterias (sea star) to move as well as to catch food. Respiration also takes place, through, water vascular system. d. Torpedo Electric organ. Torpedos are unique organisms, having two large kidney shaped electric organs. These organs are capable of generating high voltage electric shocks. e. Parrot-Perching Birds with the feet adapted (to hold tree branches are perching birds. The Passeriformes birds are true perching birds with four toes, three directed forward and one backward. f. Dog fish-Placoid scales Placoid scales are tough scales that cover the skin of elasmobranches (dog fish, sharks and rays). They are covered with hard enamel. The function of these scales is to protect against predators.