Question

Typhlosole of an earthworm is a device for
a. Extra secretion of the digestive enzymes
b. Increasing absorptive area
c. Slowing down the passage of food
d. Crushing of food

Answer 1

Hint: Earthworms have a segmented body and they belong to the phylum Annelida and they are commonly found in the soil. They are also commonly known as farmer’s friends.

Complete Answer:
Earthworm belongs to the phylum Annelida. Typhlosole is a part of the intestine and is found in the segment 26 to 95. It increases the capacity of excretion and absorption during digestion.

Option a: Typhlosole is a part of the intestine whose function is to increase the absorptive surface area. Enzymes such as amylase, cellulose, acid phosphatase, alkaline phosphatase, and nitrate reductase are secreted in the gut of the earthworm.

Option b: An internal median fold of the dorsal wall called, typhlosole is present in the intestine on the 26th segment. This increases the effective area of absorption in the intestine. Typhlosole is a dorsal flap of the intestine that runs along most of its length, effectively forming a tube within a tube, and thereby increasing the absorption area by that of its inner surface. Its function is to increase the intestine surface area for more efficient absorption of digested nutrients.

Option c: The function of typhlosole is to increase the absorptive surface area. Earthworm does not have teeth, however, they have liplike extension over the mouth that helps in directing food into the mouth. Inside the mouth, the muscular pharynx grabs it, coats it with saliva, and pushes it down the esophagus and then into the crop.

Option d: The digestive system of earthworm consists of the pharynx, the esophagus, the crop, the intestine, and the gizzard. In the gizzard, the food is crushed by strong muscular contractions and mineral particles by the worm.

Thus, option b) Increasing absorptive area is correct.

Note: It is to be noted that typhlosoles also occur in bivalve mollusks, lampreys, and echinoderms. Typhlosole in general helps in increasing the surface area of absorption.