What is hemichordata
Answers
H-e-m-i-c-h-o-r-d-a-t-a is bilaterally symmetrical and t-r-i-p-l-o-b-l-a-s-t-i-c animal. They are exclusively marine animals. They can be solitary or in colonies. H-e-m-i-c-h-o-rd--a-t-a have a true body cavity or c-o-e-l-o-m. The digestive tract is complete with an anus and can be in the form of a U shaped tube or straight.
marine d-e-u-t-e-r-o-s-t-o-m-e animals, generally considered the sister group of the echinoderms. They appear in the Lower or Middle Cambrian and include two main classes: E-n-t-er-o-p-n-e-u--s--t-a, and P-t-e-r-o-b-r-a-n-c-h-i-a
The body of acorn worms is worm-shaped and divided into an anterior proboscis, an intermediate collar, and a posterior trunk. The proboscis is a muscular and c-i-l-i-a-t-e-d organ used in locomotion and in the collection and transport of food particles. The mouth is located between the proboscis and the collar. The trunk is the longest part of the animal. It contains the pharynx, which is perforated with gill slits (or pharyngeal slits), the esophagus, a long intestine, and a terminal anus. It also contains the gonads. A post-anal tail is present in juvenile member of the acorn worm family H-a-r-r-i-m-a-n-i-i-d-a-e.
In the genus R-h-a-b-d-o-p-l-e-u--r-a, z-o-o-i-d-s are permanently connected to the rest of the colony via a common stolon system.
They have a d-i-v-e-r-t-i-c-u-l-u-m of the f-o--r-e--g-u-t called a
s-t-o--m-o-c-h-o-r-d, previously thought to be related to the chordate -
n-o-t-o-c-h-o-r-d, but this is most likely the result of convergent evolution rather than a h-o-m-o-l-o-g-y. A hollow neural tube exists among some species (at least in early life), probably a primitive trait that they share with the common ancestor of c-h-o-r-d-a-t-a and the rest of the
d-e-u-t-e-r-o-s-t-o-m-e-s
Kingdom: A-n-i-m-a-l-i-a
C l a d e: A-m-b-u-l-a-c-r-a-r-i-a
Phylum: H-e-m-i-c-h-o-r-d-a-t-a
B-a-t-e-s-o-n, 1885
Answer:
Body is , soft unsegmented worm like and bilaterally symmetrical. these animals possess a combination of notochord and cordate characters
Body is divided into proboscis collar and trunk
These animals resemble chordates only in having pharyngeal gill- clefts or gill slits and they lack notochord and true dorsal nerve cord. gill slits form the respiratory system and connects the pharynx with outside.
'Buccal diverticulum' earlier regarded as " notochord " is present in proboscis.
No nephridia . Single Glomerulus connected to blood vessels has a excretory function.
Exclusively marine, solitary or colonial , moatly tubicolous and detritus feeders like the earthworm
Example:- Balanoglossus...