Question

Chitinous exoskeleton and metameric segmentation are features of the phylum

• A. Annelida and Arthropoda, respectively
• B. Arthropoda and Aschelminthes, respectively
• C. Annelida and Aschelminthes, respectively
• D. Arthropoda and Annelida, respectively

Answer 1

The correct option is D Arthropoda and Annelida, respectively

The arthropods such as crustaceans have a hard skeleton outside their body which is made up of chitin which is a type of carbohydrate. Chitinous exoskeleton is impermeable to water and protects the insect from desiccation. Arthropods are also segmented but it is only confined to the ectodermally derived tissue.

Annelids have metameric segmentation. Metamerism is the phenomenon of having a linear series of body segments fundamentally similar in structure. Here, the segments are extended upto the mesodermally derived tissue.

Aschelminthes are roundworms and are devoid of segmentation and chitinous exoskeleton.