Question

Which of the following about segmentation is/are true?

• A. Segmentation is also known as metamerism
• B. Humans exhibit homomeric segmentation
• C. Segmentation is found only in invertebrates
• D. Metameres could be either similar or different

Answer 1

Answer: (A), (D)

Metameres could be either similar or different

The concept of segmentation in biology relies upon the ability for organisms to duplicate organs and structural elements. Each segment is known as a metamere. Segmentation or metamerism allows for a greater degree of variety among species. In biology, the segmentation follows the longitudinal axis (the length of the body from head to tail) and separates the different body functions into separate systems such as the circulatory, digestive, nervous and excretory systems. For example, humans exhibit heteromeric segmentation, in which each segment differs from another and fulfills a specific role. Homomeric segmentation is concerned with segments that contain similar elements, and replicate each other in function. Earthworm (an Annelid) is an excellent example of homomeric segmentation. Invertebrates such as annelids and arthropods, and most chordates exhibit segmentation at some point of development.