181. Nephridia are excretory organs in
(A) round worms
(B) lizard
(C) earth worm
(D) planaria

182. Which one is harmful mollusc
(A) slug
(B) snail
(C) oyester
(D) star fish

183. Which structure is involve in gaseous exchange of plants
(A) stomata
(B) lenticels
(C) cuticle
(D) all of these

184. Common feature of human and insect trachea is
(A) non-collapsiable wall
(B) supporting rings
(C) ectodermal origin
(D) endodermal origin

185. Vomiting occurs due to
(A) constipation
(B) diarrhoea
(C) antiperistalsis
(D) peristalsis

186. Photosynthetic prokaryotes lack
(A) ribosomes
(B) chloroplast
(C) cell-membrane
(D) vacuole

(A) crop
(B) syrinx
(C) stomach
(D) gizzard

 188. The scientific name of jelly fish is
(A) Aurelia
(B) Madrepore
(C) Actinia
(D) Obelia

189.  In which plants leaves are always in whorls
(A) lycopsids
(B) psilopsids
(C) sphenopsids
(D) pteropsids

(A) platelets
(B) RBC’s
(C) antibodies
(D) WBC’s