Question

Which one genus, it's two characters and phylum are not correctly matched, whereas the remaining three are correct
A. Pila- Body segmented
Mollusca- mouth with radula

B. Asterias- Spiny skinned
Echinodermata- water vascular system

C. Sycon- Pore bearing
Porifera - Canal system

D. Periplaneta-Jointed appendages
Arthropod- chitinous exoskeleton

Answer 1

The character of segmentation which is also referred as metamerism is a condition where there are repeating parts in a linear series, each of the segment is called metamere or somite, it is formed always in a sequence in an embryo, i.e from anterior direction to posterior direction.

Complete answer:
Pila is a freshwater snail which belongs to the family Ampullariidae. It is a member of phylum Mollusca. The members of phylum mollusca have an unsegmented body.
Asterias or starfish is a member of the family Asteriidae. It is a member of phylum Echinodermata. It is known to have a hydraulic water system for the process of locomotion, for the purpose of feeding as well as respiration.
Sycon belongs to calcareous sponge which is from the family Cottidae. They are members of Phylum Porifera. The term porifera means pore bearing. It has a characteristic canal system that is helpful in locomotion, for feeding as well as reproduction.
Periplaneta (class- insect) belongs to phylum Arthropoda. They have jointed appendages as well as exoskeleton made up of chitin.

Hence, the correct answer is option (A)

Note: The body plans in case of phylum Annelida, Arthropoda and Chordata . These three phyla have segments that are formed by using a "growth zone". This growth zone is responsible for directing and defining segments. All the three phyla have a segmented body plan and are known to use a growth zone, however, there are different mechanisms used for generating these patterns.