Question

characteristic of plylum ashelminthes​

Answer 1

$\huge \mathfrak \red {answer}$

________________

$\huge \bold\orange {Aschelminthes}$

➡️ The body of these organisms is unsegmented and triploblastic.

➡️They have a pseudocoeloem, where the body cavity is not lined by the mesodermal layer.

➡️They are bilaterally symmetric.

The body is cylindrical or thread like with elongated, slender worm-like appearance and tapering at both ends.

➡️Body wall has epidermis, muscle layer and is covered by cuticle.

➡️The body size of these organisms varies from microscopic to several centimetres in length.

➡️These organisms are mostly parasitic, with a few free-living

➡️They exhibit an organ system level of organization.

➡️Externally, there is little differentiation between the anterior and posterior regions. But internal cephalization is present.

➡️There is no distinct head. However, the mouth is present in the anterior

➡️The digestive system is complete, with a mouth and anus.

➡️The mouth in these organisms is terminal and is surrounded by lips bearing sense organ.

➡️Amphids and papillae are the main sensory organs.

➡️The nervous system consists of a nerve-ring that encircles the oesophagus. From it, nerves extend out anteriorly and posteriorly.

➡️Respiratory organs are absent.

➡️Respiration occurs through the general body surface. It is aerobic in free-living forms and anaerobic in parasitic organisms.

➡️Sexes are separate and are unisexual, exhibiting sexual dimorphism.

➡️Fertilization is internal.

➡️They are ovo-viviparous, oviparous or viviparous.

➡️The life cycle of these organisms is complicated. It may be with or without an intermediate host.

________________

@MissCrazy

Answer 2

Answer:

Explanation:

1.They are also known as round worm as well as thread worm.

2.Some are aquatic while some are terresterial but most of them are parasites in plants and animals(exception =Rhabditis _it is a free living )

3.Their sense organs are amphids,plasmids and pappilae