Question

How are animal bodies "planned & organized"? 

What types of body organizations characterize animals? 

What role does symmetry play?

Answer 1

Answer. Body organisation tells about the level of the organisation in the organisms. At which level the division of labour's takes places. There are 4 level of organisation.

1. Cellular:- It is found in poriferans. Here different cells performs different functions.

2. Tissue level of organisation:- it is found in the concentrates and the ctenophora.

3. Organ level of organisation:- it is present in platyhelminthes in which different organs perform different functions.

4. Organ system level of organisation:- it is present in case of the higher animals aschelminthes afterwords.

Answer- Symmetry may be defined as the division of a organism in two halve by any planed. It is of two types . It plays a very significant role in classification and evolution. The primitive organism or animals were asymmetrical such as sponges. Afterwords there appears the symmetric organism.

In the radial symmetry, organism can be divided into two equal parts by indefinite number of plane.

In bilaterally symmetric organism, only one plane can divide the organism into 2 equal halves.