MHT CET 202621 AprilMorning Shift
- Exam
- MHT CET
- Year
- 2026
- Date
- 21 April
- Shift
- Morning Shift
- Subject
- Biology
- Chapter
- Animal Kingdom
MHT CET 2026 · 21 April · Morning Shift · Biology · Animal Kingdom
The most primitive animal with a central nervous system (CNS)...
The most primitive animal with a central nervous system (CNS) located on the ventral side of body is-------.
Options
- AHydra
- BPlanaria
- CSycon
- DScoliodon
Correct answer
B. Planaria
Step-by-step solution
Sycon belongs to Porifera and lacks a nervous system.
Hydra belongs to Cnidaria and has a primitive nervous system consisting of a diffuse nerve net, but lacks a central nervous system (CNS).
Planaria belongs to Platyhelminthes, which are the most primitive animals to exhibit cephalization and a central nervous system. Their CNS consists of cerebral ganglia (brain) and two longitudinal nerve cords located on the ventral side of the body, connected by transverse commissures to form a ladder-like structure.
Scoliodon is a chordate and possesses a dorsal, hollow central nervous system.
Answer: Planaria
Hydra belongs to Cnidaria and has a primitive nervous system consisting of a diffuse nerve net, but lacks a central nervous system (CNS).
Planaria belongs to Platyhelminthes, which are the most primitive animals to exhibit cephalization and a central nervous system. Their CNS consists of cerebral ganglia (brain) and two longitudinal nerve cords located on the ventral side of the body, connected by transverse commissures to form a ladder-like structure.
Scoliodon is a chordate and possesses a dorsal, hollow central nervous system.
Answer: Planaria