Distinguish between the following (a) Prostomium and peristomium (b) Septal nephridium and pharyngeal nephridium | NCERT solution | Class 11 Biology | Unit-7 Structural Organisation in Animals



Q.5:- Distinguish between the following
(a) Prostomium and peristomium
(b) Septal nephridium and pharyngeal nephridium

 

Answer:- 

(a)

Prostomium
Peristomium
Prostomium is a small fleshy lobe, which overhangs the mouth of an earthworm. It helps the organism push into the soil and is sensory in function. The first body segment in the earthworm is called the peristomium. It surrounds the mouth opening.

(b)



Septal nephridium
Pharyngeal nephridium
They are present on both sides of inter-segmental septa behind the 15th segment. They open into the intestines. They are present as three paired tufts in the fourth, fifth, and sixth segments.