Your lab group is charged with the identification of an unknown creature. Your lab partners believe that it is a small annelid because of its worm-like appearance. You argue it is a nematode. To convince your lab partners, you point out certain distinguishing characteristics. Check the characteristics that are associated with nematodes.

I) Nematodes lack body cavity

II) Nematodes are cylindrical but not segmented

Explanation:

The unknown creature is a nematode, and not an annelid once it has the following characterictics

- Absence of body cavity

Unlike annelids, Nematodes lack true body cavity but possess a pseudo-coelom body cavity

- Unlike annelids with cylindrical and segmented bodies, nematodes are cylindrical but not segmented.

Examples of nematodes are guinea worms, thread worms etc; while examples of annelids are earthworm and leeches.

Nermatode.

It is cylindrical in shape.

It lack cillia or flagella.

It has one or two testis and the presence of spicules.

It is bilaterally symmetrical and tripoblastic.

It has body cavity of coelom.

It has amoebiod sperm cells.

The body walls muscles is longitudinal.

It exhibit tissue level of organization.

Explanation:

Nermatodes are long thin worms also called round worms. They are unsegmented vermiform animals. Some are free living while others are parasitic. They are cylindrical in shape, have distinct alimentary canal, they moults periodically, they are tripoblastic, they are bilaterally symmetrical, their fertilization is internal and reproduction is sexual .

Unlike annelids, annelids are cylindrical but segmented.

Examples of Nermatodeinclude guinea worm, thread worm.