"Cute Silkworm Baby" PPT courseware

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"Cute Silkworm Baby" PPT courseware

Silkworms reproduce from eggs, which hatch into larvae in about 10 days. Ant silkworms grow rapidly by feeding, and their body color gradually turns pale and turns bluish white. When the larvae grow to a certain extent, they need to shed their old skin and grow a new, wider skin before continuing to grow. During the molting process, the silkworm spins out a small amount of silk, fixes its abdomen and legs on the silkworm seat, raises its head and chest, and stops moving as if it is asleep, which is called sleep.

There are four molts from the ant silkworm to spinning silk and cocooning. The ant silkworm is called the 1st instar silkworm after feeding, the 2nd instar silkworm after the first sleep, and so on, and the 5th instar silkworm after the fourth sleep. Dormant larvae do not eat or drink. When the larvae develop to the end of the fifth instar, they gradually stop feeding, the silkworm body shrinks, the digestive tract is emptied, and the silkworm becomes transparent. At this time, it is called mature silkworm.

The silkworm body is a long cylindrical shape, consisting of three distinct body segments: head, thorax and abdomen, and is bluish white.

Head: Small, located at the front of the silkworm body, oblate in shape.

Chest: consists of three links. There is a pair of thoracic legs on the ventral surface of each thoracic segment, a total of three pairs of thoracic legs.

Abdomen: It is composed of 10 links. The 3rd, 4th, 5th, and 6th segments each have a pair of gastropods. It is the locomotor organ of the silkworm, making the body move forward. There is a pair of tail legs on segment 10, which can be used to hold objects. There are 5 pairs of gastropods in total, and there is a sharp fleshy protrusion on the back surface of the 8th segment, called the tail horn. There is a small black spot on each side of the first segment of the thorax and the first 8 segments of the abdomen, which is the respiratory organ of the silkworm.

The appetite of mature silkworms decreases, the front digestive organs are empty, and the chest becomes transparent; then they stop eating completely, the body shortens, and the abdomen becomes transparent. The head and thorax of the silkworm body are raised, and the mouth spins silk strands, swinging up and down to find a place to camp. After spinning, the silkworm body was observed to become smaller and lurk inside.

The silkworm baby grabs the sleeping place with its abdomen and legs, lifts the front half of the body and remains still.

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Update Time: 2024-11-03

This template belongs to science courseware E-education edition third grade science volume 2 industry PPT template

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