- Exam
- NEET
- Year
- 2020
- Subject
- Zoology
- Chapter
- Structural Organisation in Animals
NEET 2020 · Zoology · Structural Organisation in Animals
If the head of cockroach is removed, it may live for few days...
Options
- Athe cockroach does not have nervous system.
- Bthe head holds a small proportion of a nervous system while the rest is situated along the ventral part of its body.
- Cthe head holds a 1/3rd of a nervous system while the rest is situated along the dorsal part of its body.
- Dthe supra-oesophageal ganglia of the cockroach are situated in ventral part of abdomen.
Correct answer
B. the head holds a small proportion of a nervous system while the rest is situated along the ventral part of its body.
Step-by-step solution
NERVOUS SYSTEM:
The nervous system of the cockroach consists of a series of fused, segmentally arranged ganglia joined by paired longitudinal connectives on the ventral side.
Brain: It is present in the head. It is made up of a pair of supra oesophageal which is the present above esophagus. It supplies nerves to antennae and compound eyes. The sub-oesophageal ganglia are present below the esophagus. These ganglions are connected together by paired longitudinal connectives on the ventral side.
Double Ventral Nerve Cord: They arise from sub-oesophageal ganglia and run-up to the posterior end of the body. These nerve cords are connected with the help of 9 pairs of segmented ganglion three in the thorax and 6 in the abdominal segment.
The nervous system of cockroaches is spread throughout the body. The head holds a bit of the nervous system while the rest is situated along the ventral side of the body.