phylums

1. PHYLUM NEMATODA
By Kanwal Nisa

2. Nematoda :
The organisms belonging to the phylum
Nematoda are also known as
“roundworms”.
There are 28000 species of Nematoda
identified till date.
They are unsegmented vermiform
animals.
The epidermis has dorsal and ventral
nerve cords.

3. Characteristics of nematodes:
Following are the important characteristics of Nematoda:
Their body is bilaterally symmetrical and triploblastic.
They are cylindrical in shape . They exhibit tissue level organization.
Their body has a cavity or pseudocoelom.
The alimentary canal is distinct, with the mouth and the anus.
They are sexually dimorphic . They are devoid of the circulatory system and respiratory
system.
They are free-living or parasitic . Parasitic nematodes cause diseases in the host .
Fertilization is internal and reproduction is sexual.
Their cuticle moults periodically.
The epidermis is synctical and contains dorsal or ventral nerve cords.
of species and their interaction with the environment to support life.

4. Characteristics of Nematodes:
The body-wall muscles are longitudinal . They possesse amoeboid sperm cells.
They consist of chemosensory organs called aphids situated on Nematode – Structure,
Classification and Characteristics Nature is a blessing to us.
The biosphere is the area of the earth that contains both living and nonliving organisms.
It is home to a wide range of species that all rely on one another.
Biological diversity refers to the interdependence