List major characteristics of animals-Are heterotrophic, multicellular, use absorptive nutrition, have no cell walls, usually have nerves, muscles and the ability to move2. Explain possible reasons why the Cambrian Period led to a rapid increase in animal diversity

Answer No 1:

The major characteristics of animals are:

Heterotrophic Multicellular Absorptive nutrition No cell walls Usually have nerves, muscles, and the ability to move Tissues develop from embryonic layers

Answer No 2:

There are a number of reasons why the Cambrian Period led to a rapid increase in animal diversity. Some of the reasons are:

The environmental conditions during the Cambrian Period were favourable to support the growth of animals and hence increase animal diversity. There was an increased supply of oxygen which enabled animals to survive. During the Cambrian Period, the Hox gene complex evolved. Thus gene complex was unique to animals and allowed for new morphologies in animals. There was evolutionary 'arm race' between the predators and preys during this period.