Question

Select the incorrect statements with reference to the nervous system in Periplaneta.
(I) The brain is mainly a sensory and an endocrine centre.
(II) All thoracic ganglia supply nerves to the parts of their respective segments only.
(III) The sixth abdominal ganglion is the largest of all the abdominal ganglia.
(IV) The frontal ganglion is connected to the ingluvial ganglion by a recurrent nerve.

• A. II, IV
• B. II, III
• C. I, III
• D. IV

Answer 1

The correct option is D IV

Periplanta is a genus of cockroaches. Supra oesophagal ganglia or brain is present on the dorsal side of the oesophagus. The brain is mainly a sensory and an endocrine center releasing hormones into the haemolymph. Thoracic ganglia supply nerves to the legs and the wings. Thoracic ganglia supply nerves to the parts of their respective segments. The largest abdominal ganglia is the sixth ganglion present in the seventh segment. The frontal ganglion is connected. A medial hypocerebral ganglion is connected to the frontal ganglion by the recurrent nerve. So, the correct option is D.