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2-These organic debris : a- form hard structures and are referred to as
the buttress zone.
b-form rocks and are referred to as Limestone.
3-coral reef is an organically constructed wave resistant rock structure :
a- Created by carbonate secreting organisms.
b- Nitrogen secreting organisms.
4-Corals belong to Phylum : a- Cnidaria.
b-Ctenophora.
5-the rigid
exoskeleton that protect the coral poly pis called : aTentacles.
b-corallite.
6-the corallite is divided into compartement by vertical partitions
called : a- septa.
b-ctnes.
7-Polyps live : a- As solitary individuals.
b-in a colony.
c- Either as solitary individuals or in a colony.
8-the coral’ s waste can be used by the zooxanthellae for
photosynthesis : a- true.
c- False.
9-when food is scarce , the zooxanthellae : a-can be digested by the
coral.
b-The coral can not digest the zooxanthellae.
10-the coral : a- rely only on zooxanthellae for food.
b-supplement its diet by preying on small zooplankton.
11-Hermatypic corals : a- do not possess zooxanthellae.
b-possess zooxanthellae.