ncert solutions of chpter 4 class 11th
Answers
12.
produced by mothers so that even under harsh environmental conditions, some eggs might be able to survive and produce young ones. On the other hand, in viviparous organisms, the development of young ones takes place in safe conditions inside the body of the mother. They are less exposed to environmental conditions and predators. Therefore, there are more chances of their survival and hence, less number of young ones is produced compared to the number of eggs.
Question 13: Segmentation in the body is first observed in which of the following: (a) Platyhelminthes (b) Aschelminthes (c) Annelida (d) Arthropoda
Answer 13: The body segmentation first appeared in the phylum, Annelida (annulus meaning little ring).
Question 14: Match the following: (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
Answer 14: Column I Column II (a) Operculum (viii) Osteichthyes (b) Parapodia (v) Annelida (c) Scales (iv) Reptilia (d) Comb plates (i) Ctenophora (e) Radula (ii) Mollusca (f) Hairs (vii) Mammalia (g) Choanocytes (iii) Porifera (h) Gill slits (vi) Cyclostomata and Chondrichthyes .
