Question

In Cockroach nerve cord ganglia are

• A. Two pairs thoracic and four pairs abdominal
• B. Three pairs thoracic and six pairs abdominal
• C. Three pairs thoracic and five pairs abdominal
• D. Two pairs thoracic and seven pairs abdominal

Answer 1

Answer: (B)

Three pairs thoracic and six pairs abdominal

In cockroach, the sub-oesophageal ganglion arises a double nerve cord which travels through the thorax and abdomen below the alimentary canal on the ventral side up to the posterior end of the body. The nerve-cord has three large ganglia in the thorax, one each for pro-, meso-and metathoracic segments, therefore, they are called prothoracic, mesothoracic and metathoracic ganglia.

The nerve cord has six ganglia in the abdomen which lie in the 1st, 2nd, 3rd, 4th, 5th, and 7th segments. In Cockroach nerve cord ganglia are three pairs of thoracic and six pairs of abdominal.

So the correct answer is 'Three pairs thoracic and six pairs abdominal'.