The presence of a notochord and paired pharyngeal gill slits are the characteristic features of the phylum Chordata. In sub-phylum Vertebrata, the notochord present in embryos gets replaced by a cartilaginous or bony vertebral column in adults. Thus, it is said that all vertebrates are chordates but all chordates are not vertebrates.
Answered by Pragya Singh | 1 year agoPrepare a list of some animals that are found parasitic on human beings.
Match the following:
| Column I | Column II |
| (a) Operculum | (i) Ctenophora |
| (b) Parapodia | (ii) Mollusca |
| (c) Scales | (iii) Porifera |
| (d) Comb plates | (iv) Reptilia |
| (e) Radula | (v) Annelida |
| (f) Hairs | (vi) Cyclostomata and Chondrichthyes |
| (g) Choanocytes | (vii) Mammalia |
| (h) Gill slits | (viii) Osteichthyes |
Segmentation in the body is first observed in which of the following:
(a) Platyhelminthes
(b) Aschelminthes
(c) Annelida
(d) Arthropoda
Could the number of eggs or young ones produced by an oviparous and viviparous mother be equal? Why?
What are the modifications that are observed in birds that help them fly?