Biological experiments to observe earthworms 15, biological experiments to observe earthworms

Purpose: 14 pages.

Materials and utensils: 14 pages of the book.

Method steps: 14 pages of the book.

Conclusions:1Answer: The earthworm body is segmented, and there are 13 links from the head to the segment (the segment is composed of 14-16 segments).

Question 2 Answer: There is a sensation in the abdomen that hinders the movement of the hand, and that is because of the presence of bristles.

3.The earthworm moves on the rough paper, first shortening and thickening, and after the bristles fix the body, the body is elongated and thinned.

4。Movement on glass is not as strong as rough paper movement because the bristles are not easily fixed to the glass.

5.There is mucus on the body. That's because earthworms breathe by secreting mucus to keep their body walls moist.

Discuss Answers:1Earthworms are suitable for burrowing in soils rich in humus with a certain temperature and humidity, little change in temperature difference.

It is generally diurnal and nocturnal. Earthworms are hermaphroditic animals that are allogeneically fertilized. Relying on the coordinated movement between the annular muscles, longitudinal muscles and bristles in the body wall, it feeds on organic matter such as dead branches and leaves in the soil.

2.Earthworms do not have a respiratory system and rely on mucus-secreting moist body walls for breathing. Earthworms have capillaries on the body wall, and the blood contains hemoglobin, which can carry oxygen.

Atmospheric oxygen dissolves in the mucus of the body wall and then enters the capillaries of the earthworm body wall for gas exchange. If the surface of the earthworm is dry, it will not be able to perform the above functions. After heavy rains, too much rain will squeeze the air out of the soil, so the burrowing earthworms are forced to crawl to the surface to breathe.

3.The animal body is segmented, which can make the body move flexibly, freely and easily. The body segments of earthworms have the above functions. The ends of the earthworm bristles can be in contact with the rough surface of the surrounding environment to support and coordinate with the ring and longitudinal muscles to complete the movement.

4.Deep moist soil can provide earthworms with suitable conditions for survival, living and reproduction, generally including suitable temperature, humidity, gaseous oxygen, food and habitat that is convenient for avoiding enemies.

The first time the earthworm may contract, the second time the reflection is not obvious , since its neural structure is mostly distributed in the front end.

The earthworm will run to the place where there is no cotton ball, and it will go backwards before you put it, which shows that the creature is stressful and seeks to take advantage and avoid harm.

The experimental procedure is as follows:

1. Take two mineral water bottles and cut them into cups, respectively fill the darker clay, the middle is filled with lighter sand, and the upper layer is filled with darker clay, each layer is slightly pressed, and the soil of the mineral water bottle is kept at a certain humidity, and the total volume of the three layers of soil accounts for about three-quarters of the volume of the glass cylinder, so as to keep the bottle with enough air.

2. Choose a few good earthworms.

Place in a bottle with earthworms in it.

3. Put the above device in a warm and dark place for 5-6 days to observe the stratification and looseness of the soil.

1) On the first day of observation, it was very smooth, the earthworm burrowed into the soil, and there was no change.

2) On the third day of observation, there was no change in the sandy soil without earthworms, and the sandy soil with earthworms gradually merged.

3) On the sixth day of observation, the changes were obvious, the sandy soil with earthworms was obviously fused together, and the soil voids became larger and softer.

Experimental conclusion: The impact of earthworms on the environment is that earthworms dig holes to loosen the soil, decompose organic matter, create good conditions for the growth and reproduction of soil microorganisms, and promote acidic or alkaline soil to become neutral soil, increase phosphorus and other available components, and make the soil suitable for the growth of crops. In terms of soil improvement, elimination of pollution, protection of the ecological environment, material cycle, biodiversity.

At present, many countries use earthworms to dispose of household waste.

Organic waste and purified sewage.

Earthworms contribute to the material circulation and energy transfer of soil processes through activities such as feeding, digestion, excretion, secretion and burrowing, and are soil invertebrates that have an important impact on many processes that determine soil fertility.

One of the taxa, known as ecosystems.

Engineer.

The earthworm breathes oxygen in the air Oxygen is first dissolved in the mucus of the body wall, and then penetrates into the blood in the capillaries in the body wall, and the carbon dioxide in the blood is also excreted through the body wall Therefore, the earthworm breathes with the moist body wall, and breathes the oxygen in the air Therefore, during the observation process, the earthworm body surface should be gently rubbed with a wet cotton ball to keep the body surface moist This is because the earthworm relies on the moist body wall for breathing

So the answer is: so that the earthworm can breathe smoothly.

Categories: Leisure Hobbies >> Flowers, birds, fish and insects.

Problem description: Can an earthworm avoid an obstacle in time?

Will the earthworm untie itself after it is knotted (artificial)?

What is a continuous black line in an earthworm?

Do earthworms have darker backs than their bottoms?

Do earthworms have more blood near the tip?

Can earthworms live in water?

Analysis: Earthworms cannot avoid obstacles far away in advance because they have no vision, and their sensitive sense of touch cannot detect obstacles at a distance;

After the earthworm is knotted, if the knot is relatively loose, it will untie itself by twisting and wriggling; If the knot is tied very tightly, it will probably not be opened, and it will die because of it;

One of the continuous black lines in the earthworm's body is its dorsal nerve cord, which has no spine;

The color of the back of the earthworm is not darker than the color of the bottom, because they usually bury their entire body in the soil, and the different body colors are of no significance to it;

Earthworms do not have the problem of more abundant blood in the proximal apex, and as a lower animal, they do not actually have a morphological brain, so there is no need to concentrate blood on the cephala;

The earthworm should not be old enough to live in water, because it has no underwater breathing organs.

1. Temperature-loving: 15 -25 is the best temperature, in order to create the best temperature, buckle the plastic greenhouse or cover the plastic sheet in winter, cover the straw in summer, sprinkle more water to cool down, 0 -5 hibernation, freeze to death below 0, die more than 40, stop growing above 32, buckle the shed on October 25 in Beijing, cover the plastic sheeting, and remove it on April 10 of the second year, so that the earthworm grows to December 20, and then to February 10 of the next year, basically in dormancy, from February, to prevent the earthworm from escaping due to high temperature, Pay attention to the timely unveiling after 10 days, and gradually turn to the best temperature, at this time pay special attention to the plastic cloth on high temperature days. At this time, it is the hardest, uncover the plastic sheet around during the day, cover it in time in the morning and evening, and water and moisturize in time, so that from March to June 10 is the peak spring spawning period for earthworm growth, high temperature period, to prevent heatstroke and cool down, it is best to water once a day, August 206 10 to August 20 is after the summer day to gradually enter dormancy.

At the end of September, earthworms spawn at their second peak.

2. Moisture-loving, afraid of dryness: earthworms have a water content of about 80%, and the water content of bait is required to be 60%-80% (to hold the material by hand, and the finger seam drips shall prevail), so the water content of the breeding bed is required to be more than 60%, so that every day or every 1-2 days, it must be watered once, the water is not too large, but it is necessary to water thoroughly and connect the lower layer of material, and the watering time is to water at noon in winter, water at night in summer, and water during the day in spring and autumn.

3. Afraid of darkness and light: earthworms are nocturnal and can be seen in the moonlight for active foraging, and the breeding bed should be covered with straw to keep it moist and shading.

4. Like air, like quiet, loose bait is conducive to the growth of earthworms, our many years of experience is to turn the bed over (about 20 cm thick) before feeding to increase ventilation. This is important because over the years, we have found that the number of earthworms in the bottom of the bed soil is very small, but the bait is still available, mainly because of the lack of air, which is not good for the growth of earthworms.