Question

Which of the following is true or false

1) Within the Bilateria, the Protostomes include two major groups of organisms, the Lophotrochozoa and the Ecdysozoa. The segmented worms (Phylum Annelida) molt their outer cuticle and belong to the Ecdysozoa.

2) A major route of evolutionary diversification among the four Classes of the Phylum Cnidaria resulted from the reduction or loss of one phase of the complex life cycle.

3) The basal (“primitive”) Classes of the Phylum Crustacea are characterized by elongated bodies and relatively undifferentiated appendages down all or part of the body, and often live today in harsh or low diversity refuge environments (caves, intertidal mudflats, ephemeral fresh water habitats).

4) Primates are more closely related to rodents and rabbits than they are to cats, dogs, and weasels.

Answer 1

Ans 1 and 4 are true

1. Protostomes are two subgroups, the lophotrochozoa, which includes the annelids (e.g., segmented earthworms and leeches) and mollusks and the ecdysozoa to which the arthropods and nematodes .so it is false.

2. Cnidarians have a life cycle of two forms. One is a free-swimming jellyfish medusa stage and the second is polyp stage. The class Anthozoa includes all cnidarians that exhibit a polyp body plan only I.e, there is no medusa stage within their life cycle.so,evolutionary diversification occurred in cnidarians by loss of one phase of life cycle.

3. The primitive classes of sub phylum crustacea( phylum is arthropoda) are Class Cephalocarida and Class Branchiopoda. These crustaceans have an elongated body and the body of crustaceans is divided into the head and the trunk. The head has five pairs of appendages. They live in extreme habitats,

4. Primates are most closely related to rodents (mice, rats, beavers) and lagomorphs (rabbits and hares) than to dogs and cats