Question

write the characteristics of platyhelminthes, nematode, annelida and arthropoda with diagrams?​

Answer 1

Answer:

Characteristics of Platyhelminthes :

• the organisms belonging to this phylum are mostly parasites like liverflucks. some are free living (e.g. planarians) either aquatic or terrestrial.
• the body is bilaterally symmetrical.
• the organism has three germ layers that is why they are called triploblastic.
• the body is soft and Ribbon like and is are dorsoventrally- flattered. that is why animals belong to this phlya are also known as flatworms.
• they Mainly respire anaerobically. (Liverflucks)

Characteristics of Nematode:

• the body of these organism is cylindrical rather than flattened.
• the body of nematodes is bilaterally symmetrical and triploblastic.
• the organisms do not have respiratory and excretory system.
• sexes are separate they produce only by sexual method.
• the body wall is covered with though resistance cuticle. (Roundworm)

Characteristics of Annelida:

• Annelids are bilaterally symmetrical having true coelom.
• they are triploblastic .
• the body is elongated and segmented.
• the body has setae or parapodia for locomotion.
• Annelids reproduce sexually. some organisms are bisexual i. e. sexes may be united as (in earth worm) but some are unisexual that means sexes are separate, e. g. Nereis. (Leech)

Characteristics of Arthropoda:

• they are bilaterally symmetrical.
• there is an open circulatory system in which blood does not flow in well defined blood vessels.
• they have joint legs for locomotion one pair each on some or all body segments.
• the exhaust curtain of these organisms is made up of chitinous cuticle which sheds at periodic intervals this process is called moulting.
• sexes are separate and the development of animal involve metamorphosis. (Butterfly)