When an earthworm is placed on rough paper, what are the changes in the thickness and length of the

Earthworms on rough paper.

The body can become thicker and thinner, elongated and shortened, and the forward movement speed is relatively slow compared to the movement on the glass plate.

On the glass plate, the earthworm's body can become thicker and thinner, elongated and shortened, and the forward movement speed is relatively faster than that on rough paper.

The movement of the earthworm and the contraction and relaxation of the muscles in the earthworm body wall and the mucus on the body surface reduce the friction during exercise. Relate.

Earthworms are annelids, and their body thickness and length change with the environment. On rough paper, the body of the earthworm becomes thicker and shorter, which is caused by the rubbing of the earthworm's bristles and attachment organs on the rough paper. Specifically, when an earthworm moves on the rough paper, its bristles rub against the rough paper, creating a kind of resistance that makes the earthworm's body need more muscles to overcome this resistance.

The body of the earthworm grows cylindrical, composed of many somites, the earthworm has many somites on its body, and the body moves through the cooperation of muscles and bristles, and the body segmentation can enhance the flexibility of movement, which is a typical annelid.

The earthworm movement mode is peristaltic contraction. Several somites form a group, one group of medial longitudinal muscles contract, the ring muscles relax, and the somites shorten, while pressure in the body cavity increases, and bristles stick out to attach. In the adjacent somite group, the annular muscle contractions, the longitudinal muscle relaxes, the somites lengthen, the pressure in the body cavity decreases, and the bristles are retracted.

Each somite group alternately contracts the longitudinal and annular muscles with the adjacent somite group, causing the body to move forward in waves. The earthworm can advance 2-3 cm with each contraction, and the direction of contraction can be reversed, so it can do backward movements.

The body cavity is well developed, and at the same time, it is also divided into body chambers arranged in segments by a well-developed diaphragm. There are small holes and sphincter muscles in the diaphragm to control the flow of fluid from one somite to another. When the muscles of the body wall contract, the diaphragm muscle regulates the pressure in the body cavity and assists in the extension of the somite.

There is a dorsal foramen at the intersegmental sulcus in the dorsal midline of the body, and the discharged body cavity fluid can moisten the body surface. Body cavities also contain body cavity cells, proteins, and other particles in suspension.

If you look closely, you'll see that earthworms are actually ringing in circles, and they're annelids, while the linears are all smooth, and they don't go around and around.

Well asked, I know as much as you do.

The body of the earthworm is round and elongated, and is made up of many similar annular somites;

The bristles are locomotor organs, which have the role of supporting, fixing the body and coordinating movements when crawling in the burrow or on the ground, and the earthworm makes the body squirm through the contraction of muscles and the assistance of bristles.

The role of bristles is to increase friction.

The shape of the earthworm is linear, and the side piece is cut into a ring type.

Hello dear, I'm glad to answer for you: what makes an earthworm thicker and shorter? A:

Salt is OK. Earthworms are raised from fermented and rotted cow dung. When raising earthworms, prepare a small cement pond with a volume of 50 cubic centimeters, or replace it with utensils.

Also put 10 cm of sediment at the bottom of the pool, and then put in 20 cm thick cow dung, which must be rotten. The earthworm seeds are scattered on cow dung, and then covered with a layer of relatively thin sand and sprinkled with an appropriate amount of rice washing water. In the later stage, feed once every three to five days, and sprinkle an appropriate amount of rice washing water each time.

The thicker part of the anterior part of the earthworm's body is called"Ring belt"。The body of the earthworm is slender and consists of more than 100 somites The anterior segment is slightly pointed, the posterior end is slightly rounded, and there is a segmented inconspicuous ring at the front end The anterior end is about 13 segments close to the annular belt, and the posterior end is far from the annular belt, so the main basis for distinguishing the anterior end and the posterior end of the earthworm is the position of the annular band.

There are bristles in the middle of most body segments on the ventral surface of the earthworm, and the bristles have the effect of assisting movement Therefore, when gently touching the earthworm's body surface back and forth with your hand, there will be a rough and uneven feeling, because you touch the bristles on the earthworm's body surface The movement of the earthworm is completed by relying on the interaction and contraction of the longitudinal and annular muscles and the cooperation of the bristles on the body surface The whole body of the earthworm seems to be made up of two inner and outer tubes together, the outer tube is the body wall, and the inner tube is the digestive tube The cavity between the body wall and the return wheel of the digestive tube is the body cavity. There is body cavity fluid in the body cavity

So the answer is: bristles; Motion; body wall; digestive tract; Body cavities

Earthworms rely on bristles to roll in spring.

Before preparing on the glass plate, the bristles cannot be pierced into the glass plate.

So you can't exercise.

So the movement is fast on rough cardboard. Wish.