2-the ……………. provides support “it acts like our backbone”and increases swimming efficiency.

3-Present only in the embryos of vertebrate chordate where a bony structures called ……………….. develop near the notochord and eventually replace it during embryogenesis.

4-The …………… Pairs of opening through the pharynx.

5-In ……………………… notochord is a buccal diverticulum called a …………..………meaning “mouth-cord”

6-…………………. are marine animals formerly

WAS considered a subphylum of chordates,

based on their possession of gill slits

and a rudimentary notochord

8-In hemichordata buccal diverticulum in the posterior part of ……………...

9- In hemichordata class of ……………….. is free-moving and have burrowing habits?

10- In hemichordata.The digestive system is …………….?

12-in Hemichordata Colonies form by 1-……………………….. in pterobranchs and 2-………………… in enteropneusts.

13-In hemichordata A 1-…………….. glomerulus connected to blood vessels may have excretory function and is considered a 2-……………...

14- acorn worm is type of class ………….?

15-Hemichordates are largely ……………… feeders.

17-Fertilization is ……………. in Class Enteropneusta

18-Many individuals of ………………… live together in collagenous tubes, which often form an anastomosing system.

19-In Cephalodiscus At the proboscis base are …………………….. of branching arms with tentacles containing an extension of the coelomic compartment of the mesosome, as in a lophophore.

20-In …………………. which is smaller than Cephalodiscus, individuals remain together to form a colony of zooids connected by a stolon and enclosed in secreted tubes.

notochord is mainly composed of…………?