Question

There are nine major phyla described - Mollusca, Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Echinodermata, and Chordata,

1. which of these do you consider to be the most successful?

2.Explain your rationale for measuring success (e.g. total numbers, numbers of different species within the phylum, adaptability, specificity etc) and choose a representative animal within that phylum and discuss which aspects of its physiology and lifestyle have contributed to its success.

Answer 1

Question

1. The most successful phyla is "arthropods ".

2. The reasons for their success are :

I. Most diverse animal phylum available on land.

II. This animal phyla live in greater range of habitat.

III. Their body structure is modified in such a way that it help them to survive extreme environmental conditions.

IV. Their body segments are more specialized to perform more than one function.

V. Their number of species of Arthopoda is highest among all other animal phylum. Total 1 million species of Arthopoda is present.

For example, insect is largest group of arthopods. The diversity of insect is largest of all biodiversity present . This diversity is associated with specific body size, body form and behavior. The most important reason is presence of exoskeleton that act as protective shell to withstand adverse environmental conditions. Also, their body size is so balanced that they enable them to escape from their enemies and dispersal to new environment.