Question

The arrangement of parts in an organism in such a way that the structure can only be divided into similar halves along one plane is known as
A. Uniplanar symmetry
B. Radial symmetry
C. Bilateral symmetry
D. Unique symmetry

Answer 1

Hint: It is a type of symmetry which is found in most of the organisms in which a line of symmetry is responsible for distributing or dividing the organism's body into two halves i.e. right and thee left sides along with a tail and head which is present in addition to the bottom and top.

Complete answer:
According to a relatively basic level of classification, true animals can be primarily categorized into three groups depending on the type of symmetry that their body has:
Radial symmetry: Around the central axis, the arrangement of body parts just like the pieces in a pie or the rats on a Sun. This type of symmetry is the radial symmetry. The animals that have the radial type of symmetry only have the top and bottom surfaces but they do not have front or back sides or the left or right sides.
Bilateral symmetry: It is an arrangement of parts which are distributed in equal halves about a vertical plane or the unique plane running from head (top) to tail (bottom). Bilateral symmetry has the property of being divisible in equal symmetrical halves on both the sides along one plane. For example, humans.
Asymmetry: The organisms which lack any kind of external symmetry. These organisms are referred to as asymmetrical.

Therefore, the correct option is (c) bilateral symmetry.

Note:
Some of the important facts regarding the types of symmetry found in organisms include:
With one kind of body symmetry, some of the animals begin their life evolving a distinct type as adults. For instance, sea stars have the property of being divisible bilaterally even if their adults develop a radial symmetry.
No plan symmetry or no external symmetry is found only in the members of phylum Porifera (sponges).