Explain the structure of earthworm.
Answers
Answered by
2
An earthworm is a tube-shaped, segmented worm found in the phylum Annelida. Earthworms are commonly found living in soil, feeding on live and dead organic matter. An earthworm's digestive system runs through the length of its body. It conducts respiration through its skin. It has a double transport system composed of coelomic fluid that moves within the fluid-filled coelom and a simple, closed blood circulatory system. It has a central and a peripheral nervous system. The central nervous system consists of two ganglia above the mouth, one on either side, connected to a nerve cord running back along its length to motor neurons and sensory cells in each segment. Large numbers of chemoreceptors are concentrated near its mouth. Circumferential and longitudinal muscles on the periphery of each segment enable the worm to move. Similar sets of muscles line the gut, and their actions move the digesting food toward the worm's anus
PrinceGamer:
Plz mark my answer as brainliest
Answered by
3
External structures which are visible from outside is called external features or external morphology. The important external features are as follows:
1..Shape: Earthworm is elongated, long, narrow, cylindrical or vermiform shaped. The anterior end is tapering while the posterior end is more or less blunt.
2..Body surface: Body consists of dorsal and ventral surfaces
3..Size: A mature worm measures about 150 mm in length and 3-5 mm in width.
4..Coloration:
i. Color of the body: Dark-brown in color due to the presence of porphyrin pigment which is found in dorsal surface of the body. Dorsal surface is relatively darker than ventral surface.
ii.Respiratory pigment: Hemoglobin which is found in blood plasma that gives bright color of the blood. Hemoglobin is produced by blood gland cells that are present in 4th, 5th and 6th segments
5..Segmentation: Segmentation of the body is true i.e. external segmentation corresponds to internal segmentation. Hence, the segmentation of earthworm is called metameric segmentation. Body consists of 100-120 segments.
6...Symmetry: Bilaterally symmetrical
A type of arrangement of the parts and organs of an animal in which the body can be divided exactly and equally into two halves that are mirror images of each other along one median plane only.
7..Eyes: No eyes instead of eyes phasomes act as photoreceptor
8..
Prostomium and Peristomium: Earthworm lack distinct head. The first segment at the anterior end of the body is called peristomium
1..Shape: Earthworm is elongated, long, narrow, cylindrical or vermiform shaped. The anterior end is tapering while the posterior end is more or less blunt.
2..Body surface: Body consists of dorsal and ventral surfaces
3..Size: A mature worm measures about 150 mm in length and 3-5 mm in width.
4..Coloration:
i. Color of the body: Dark-brown in color due to the presence of porphyrin pigment which is found in dorsal surface of the body. Dorsal surface is relatively darker than ventral surface.
ii.Respiratory pigment: Hemoglobin which is found in blood plasma that gives bright color of the blood. Hemoglobin is produced by blood gland cells that are present in 4th, 5th and 6th segments
5..Segmentation: Segmentation of the body is true i.e. external segmentation corresponds to internal segmentation. Hence, the segmentation of earthworm is called metameric segmentation. Body consists of 100-120 segments.
6...Symmetry: Bilaterally symmetrical
A type of arrangement of the parts and organs of an animal in which the body can be divided exactly and equally into two halves that are mirror images of each other along one median plane only.
7..Eyes: No eyes instead of eyes phasomes act as photoreceptor
8..
Prostomium and Peristomium: Earthworm lack distinct head. The first segment at the anterior end of the body is called peristomium
Similar questions