Answer:
Instead of a brain, echinoderms have a ring of nerves located around their mouth area that governs their nervous responses. This ring coordinates their motion, their eating, basically anything that requires nerve control.
Explanation:
Nematodes are wormlike organisms which can be seen with naked eye, live in water-filled pore spaces in the soil. Nematodes are in large number in the upper soil layers where organic matter, plant roots, and other resources are most abundant.
The functions of nematodes:
- Free-living nematodes decompose organic material into nutrients and cycled them in the soil by feeding on some bacteria and fungi.
- Nematodes help in distributing bacteria and fungi through the soil and along roots by carrying live and dormant microbes.
- They used as food for higher predators, soil microorthropodes.
- They eat disease-causing organisms, thus suppress their growth.
- They acts as potential bio- control agents.
Answer:
it is called tympanostomy tubes. they also help to equalize pressure
