"Linematids and Annelida" Main Groups of Animals PPT Courseware 7

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"Linematids and Annelida" Main Groups of Animals PPT Courseware 7

Independent learning and cooperative inquiry

Reading and thinking:

⑴What are the differences in the morphology of male and female roundworms?

⑵Where do roundworms infest? What are the feeding habits of roundworms?

(3) What is the body structure of roundworms? What are the characteristics of roundworms that make them suitable for parasitism in the human body?

(4) How do roundworms move?

(5) How do roundworms enter the human body? What are the dangers of roundworms? How to prevent the occurrence of ascariasis?

(6) What are the main characteristics of linear animals?

(7) What are other linear animals?

Observe and think

1. Body shape and color of roundworms

Cylindrical, slender at both ends, about 15-35 cm; the adult body is slightly pink or yellowish, with horizontal stripes on the body surface, and the tail of the male is often curled.

Milky white, reddish.

2. Morphological differences between male and female roundworms

Female: thick and long body, pointed and straight tail, strong reproductive capacity;

Male: Small body, curled tail.

What are the dangers of roundworms?

The adult life span is about 1 year. Each female worm releases about 200,000 eggs per day. The number of adult worms in the host body generally ranges from one to dozens, and some individuals can reach thousands.

Roundworms live in the human small intestine and not only compete for human nutrients, but also cause a variety of diseases. The peristalsis of Ascaris in the intestines can cause abdominal pain; the toxins secreted by Ascaris are absorbed by the small intestine, causing mental restlessness, insomnia, irritability, night terrors, teeth grinding, cramps and headaches; if there are too many Ascaris in the intestine, it can cause intestinal obstruction; Roundworms burrow into the bile duct or appendix, causing biliary ascariasis or appendicitis; sometimes the roundworms can even break through the intestinal wall, causing peritonitis; too many roundworms invade the alveoli, causing pneumonia and other diseases.

Ascariasis prevention

First: Pay attention to personal hygiene:

Don’t drink unclean water

Wash raw vegetables and fruits

Wash your hands before eating and after using the toilet

Second: Strictly manage feces:

Don't defecate in the open. The feces should be processed and used as fertilizer.

Other linear animals---pinworms

Parasite site: large intestine

Route of transmission: oral infection, retrograde infection

Adult worms often crawl to the anus at night to lay eggs, causing anal itching. After the eggs hatch in the anus, the larvae can invade the large intestine through the anus and cause retrograde infection.

Earthworm's Breath:

moist body wall

Earthworms do not have specialized respiratory organs. Their respiration depends on the body wall that secretes mucus and remains moist at all times, so it is also called body wall respiration. The process is: oxygen in the air first dissolves in the mucus on the body surface, then penetrates into the body wall, then enters the capillaries in the body wall, and is transported to every cell in the body through blood circulation. The carbon dioxide produced by the cells decomposing organic matter is Blood circulation is transported to the capillaries of the body wall, then penetrates into the body wall, penetrates into the mucus on the body surface, and is discharged from the body surface. If the earthworm's body surface dries out, the earthworm will die from suffocation. Therefore, the body surface of earthworms always remains slimy and moist.

Movement of earthworms

The body of an earthworm is segmented, which allows it to move more flexibly. The body wall of earthworms has well-developed muscles, and the muscles and setae work together to complete the movement. In addition, the intestinal wall of earthworms also has developed muscles, and the intestines can peristalsis.

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For more information about the PPT courseware "The Main Groups of Animals Nematodes and Annelida", please click the Main Groups of Animals ppt Nematodes and Annelida ppt tag.

"Linematids and Annelida" Main Groups of Animals PPT Courseware 8:

"Nematodes and Annelida" Main Groups of Animals PPT Courseware 8 Nematodes Please analyze the structural characteristics of roundworms. What are the characteristics suitable for parasitism in the human body? The body is cylindrical, with a mouth and anus; there is a cuticle on the body surface for protection, and the structure of the digestive tract...

"Linematids and Annelida" Main Groups of Animals PPT Courseware 6:

"Nematodes and Annelida" Main Groups of Animals PPT Courseware 6 Exploring Observation Observe the roundworm specimens to see the difference in shape and size between male and female roundworms, as well as the characteristics of the body color and surface. Observe the internal structure of roundworms. What structural characteristics do you think of roundworms?

"Linematids and Annelida" Main Groups of Animals PPT Courseware 5:

"Nematodes and Annelida" Main Groups of Animals PPT Courseware 5 Observation and Thinking 1. The body shape and color of roundworms are cylindrical, with slender ends; milky white, reddish. 2. Morphological differences between male and female roundworms: Female: thick and long body, straight tail; Male: thin..

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Update Time: 2024-07-02

This template belongs to biology courseware People's Education Edition Biology for Grade 8, Volume 1 industry PPT template

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