The legs of the worm are essential for movement, especially for survival. By close observation, the legs near the front of the body are slightly longer and pointed. Further towards the back of the body, the legs are shorter and more stubby. These differences may be a result of the development of the worm that is still in process. Moreover, the shape of the body follows a bilateral symmetry as one side resembles a lot like the other side. For example, on each side there are about eight brown spots with one spot on each segment piece of the body. Lastly, the worm moves in a wave-like movement. Scrunching specific parts of its body one at a time allows that part to be lifted and then shifted forward. The mechanism produces a cascade of motion within its segments in the body to encourage movement.
Comments
This is a good description,
This is a good description, but in some areas the wording is a little awkward, for example "These differences may be a result of the development of the worm that is still in process". This could be reworded as "These differences may exist because the worm is still developing" or something similar. Additionally "as one side resembles a lot like the other side" could be reworded as simply "one side resembles the other".
Perfect paragraph comment
This is a good description of the worm legs but there is a lack of evidence to support the opening statement. If you are going to open the paper saying that the worms legs are essential for survival, you should explain how with evidence.
Topic sentence
Your topic sentence makes it seem that the focus of the paragraph is about legs, rather than movement.