CATDOLL : CATDOLL: Where do snails excrete their feces?

1. Where do snails excrete feces?

I put the snails in water and they ended their dormancy because their breathing was blocked. They started to crawl to the surface of the water and drowned. The textbook page 29 shows two snails on the left in dormancy. Some snails on the right in the glass cup have woken up and are crawling on the wall of the cup.

Page 29 Observe the eating of snails Observe the eating of snails Textbooks suggest that snails should gently place the leaves on the ground and observe quietly as they eat. It is recommended to place the leaves gently and observe quietly. These requirements should be implemented in practice. Measures to protect snails' food Which textbooks suggest that snails should gently place their food on the ground and observe it and record the results of the observation. The folder on the right

Snails eat snails teeth snails eat food observation snails especially observe the snail mouth when you can ask questions to pick some leaves, skin, bread crumbs food can be a problem: snails like to eat around a few kinds of food snails choose food snails find food and so on snail eat food questions point to the snail mouth teeth tongue, snail eat food observation description teeth tongue observation need to use a magnifying glass to observe clearly through the reference of information to solve

Page 30 of the textbook: Snails choose food for observation. The textbook illustration shows the design of the observation: Vegetable leaves, apples, pears, oranges, bread and other foods are placed at equal distances around the snail. Observe which direction the snail crawls. Please note that the snail said that actual observation requires a piece of vegetable leaf, an apple, a pear, and its food illustrations are whole vegetable plants and pieces of water. The food has been placed in practice. Cucumbers, biscuit crumbs, watermelon rinds and other items have been used.

The problem of snails choosing food includes not only the habit of using, the problem of snails liking food, but also the problem of snails finding food, the problem of snails finding food, the problem of snails finding food, etc. The problem may directly lead to new observational research and new observational research design.

Observe the snails eating food. Feed the hungry snails with food. The snails react negatively.

The observation of the snail's body is developing towards the discovery of a single observation object (snail); the observation of the snail eating food is progressing to the connection between the snail and the environment, the interaction between the snail and food, raising new questions and discovering more problems. The observation and research content includes snail and temperature, snail and water (humidity), snail and light, etc. These contents have been included in this unit lesson.

Page 30 of the textbook: Continue to observe the snail eating. Continue to observe the snail eating and excreting feces. Then turn to observe the snail excretion phenomenon. The snail eating and excreting are various forms of metabolism. Plants are easy to observe. Objects are easy to observe. Help establish the concept of life. Observe the breathing of the snail. The textbook photo provides the effect: Use two fingers to gently pinch the snail shell. Twist the snail body to see the holes in the shell. The snail's breathing holes

Page 30 of the textbook: Continue to observe snails. Hope to raise them and pay attention to their reproduction, water reaction, light reaction, etc. The snails can be studied at the end of the class and should be continued with the breeding process.

(IV) Teaching suggestions

1. Exchange experiences in raising snails

At the beginning of this lesson, we first review the content of the previous lesson and then ask questions: What are the new discoveries in the process of raising snails? The teacher chooses some key points and writes them on the blackboard: snails eat cucumbers, jump in the evening, and sleep. The report submission process does not mention the hibernation of snails. The teacher needs to ask questions, that is, how to wake up the snails from sleep. In this lesson, we put the snails into warm water according to the textbook.

2. Observe snails eating

Observe the snails eating and select 1~2 hungry snails. Teachers need to prepare in advance.

Snails eat food. Crawling snails gently put down vegetable leaves and wait quietly for the snails to eat. The snails will eat the vegetable leaves immediately. During the waiting time, the teacher organizes a discussion to observe the snails eating. Two questions about snail teeth are distributed. Mirrors are provided for observation of snails eating.

Observe the snail eating its food. Choose another snail to observe. Same observation process requirements. Observation results and records. Textbook

In the process of observing snails choosing food, we must first make the discussion and observation more convincing and formulate a preliminary plan. We need to discuss: How many kinds of food should I prepare for the snail? I want to know which kind of food the snail chooses. I want to let the snail look at the textbook illustrations to inspire ideas. In actual operation, we must first place the food arrangement circle and place the snail between the food circles to observe which kind of food the snail crawls to. Will it eat the food? Repeat several times to draw conclusions

3. Observe snail excretion and breathing

Observe the snail eating process and find that the snail excretes feces. Teachers should remind you to observe: which part of the snail excretes feces and tell the snail eating and excreting feces is an important part of life for the snail to survive.

2. Where do snails excrete feces?

We can't see it next to the stoma. It only opens when we excrete. It is usually closed.

3. How do snails breathe? How do they defecate? Why are there so many different opinions?

Excretion Snails excrete near their breathing holes, called spiracles, and deposit their excrement over their bodies, through their ventral feet and mucus, which eventually leave the excrement on the ground.

The mantle cavity of a breathing snail will form an opening at the shell mouth, called the "breathing hole", which is where gas enters and exits. If you observe carefully, you will find that the breathing hole often opens and closes, just like the "nose" used by the snail to breathe; and when the snail retracts into the shell, it will still leave the opening of the breathing hole at the shell mouth for breathing. The mantle often forms a cavity that communicates with the outside world between the feet or internal organs, called the "mantle cavity". The respiratory organs of the snail are hidden in the mantle cavity. Sometimes through the snail's shell, you can vaguely see the dense network of pulmonary blood vessels under the shell, most of which are located on the front side, close to the head, which is exactly the location of the mantle cavity.

4. Does anyone know how snails poop?

Walking and pooping, small and black

5. Excretory organs of snails

At the bottom of the snail's shell is the mating hole.