"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 3

Description

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 3

Are caterpillars and butterflies the same creature?

How does a caterpillar turn into a beautiful butterfly?

Metamorphosis

During the development of insects from larvae to adults, the larvae undergo a series of significant changes in their morphology, physiology, and habits.

Reproductive development process of silkworm

1. Silkworms spin silk to make cocoons

2. 1st, 2nd and 5th instar larvae of silkworms

3. Male and female silkworm moths mating

4. Emerging silkworm moth

5. Silkworm moth laying eggs

6. Silkworm pupa

Completely perverted

The development of insects goes through four stages: egg, larvae, pupa, and adult. This development process is called complete metamorphosis. Such as: bees, ants, mosquitoes, flies, scarabs, etc.

discuss

1. How do silkworms reproduce? What are the characteristics of this reproductive method?

Oviparous reproduction is characterized by the combination of reproductive cells of both sexes to form a fertilized egg, which develops into a new individual.

2. "The spring silkworms will not run out of silk until they die, and the wax torches will turn to ashes before their tears dry up." Analyzing the development process of silkworms, what is inaccurate in this poem? Can you make it both scientific and artistic by changing two of the words?

The spring silkworm does not die after making a cocoon, but turns into a pupa that cannot eat. After a period of development, the pupa will emerge into a moth. Therefore, this poem can be changed to "Spring silkworms turn into pupae and their silk is gone."

The relationship between insects and humans

Harmful aspects:

Harmful plants:

1) Herbivorous insects account for 48.2% of the total number of insects. Agricultural pests destroy 20% of agricultural products every year.

2) Spread plant viruses and cause plant diseases.

3) Many plants lose their economic value due to damage.

Harm to humans and animals: 2/3 of human infectious diseases are spread by insects.

Advantages:

1. Provide industrial raw materials: such as silk, honey, royal jelly.

2. Medicinal, edible and feed insects: There are hundreds of species of insects that can be used as medicine. For example, cicada sloughs, cordyceps, ants, etc.

3. Cultural insects: insects that beautify or enrich people's lives, including craft ornamental insects, fighting insects and festival insects, etc.

4. Pollination increases yield: 85% of flowering plants are insect-pollinated flowers.

Many insects, such as butterflies, moths, scarabs, etc., have a role in pollination.

practice

1. Which insect develops differently from the other three? ( )

A. Mantis B. Bee

C. Spotted disc D. Bombyx mori

2. The traditional Chinese medicine cicada sloughing is the sloughing off of cicadas during development ( )

A. Skin B. Bone

C. Exoskeleton D. Carapace

3. There is an idiom called "The golden cicada sheds its shell". Can you tell which stage the cicada belongs to after it sheds its shell ( )

A. pupa B. larva

C. Cicada slough D. Adult

skill training

1. Why do insects need to molt several times during their development?

The insect's outer shell (exoskeleton) is hard and cannot expand as it grows. When an insect grows to a certain stage, the insect's exoskeleton limits its growth, so the original exoskeleton is removed, which is called molting.

2. Why are there so many mosquitoes in low-lying and watery places?

The life of a mosquito is closely related to water. Mosquitoes are born in water. They lay eggs in water. The eggs turn into larvae and live in the water. The larvae turn into pupae, float on the water, and rupture to become mosquitoes. So on the low-lying water, there are mosquitoes laying eggs and mosquitoes that have just hatched, which looks very lively.

Keywords: teaching courseware on the reproduction and development of organisms, teaching courseware on the reproduction and development of insects, new PEP eighth grade biology PPT courseware for the second volume, eighth grade biology slide courseware download, reproduction and development of organisms PPT courseware download, insects Reproduction and development PPT courseware download, .ppt format

For more information about the PPT courseware "Reproduction and Development of Biological Reproduction and Development of Insects", please click the Reproduction and Development of Biological Ppt ppt Reproduction and Development of Insects ppt tag.

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 5:

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 5 Teaching objectives: 1. Review the basic characteristics of insects; list common insects. 2. Understand and master the definition of abnormal development. 3. List common insects that undergo metamorphosis. 4. Not completely perverted..

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 4:

"Reproduction and Development of Insects" Biological Reproduction and Development PPT Courseware 4 1. Reproduction and Development of Bombyx Silkworm Reproduction and Development of Bombyx Silkworm 1. Reproductive mode Sexual reproduction 2. Development process Egg, larvae, pupa, adult 3. Complete metamorphosis The process goes through eggs, larvae, pupae,...

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 2:

"Reproduction and Development of Insects" Reproduction and Development of Biological Organisms PPT Courseware 2 Do you know how beautiful butterflies come from? Did it grow from a butterfly? How does a caterpillar turn into a butterfly? What other creatures have such strange changes? The production of silkworm...

File Info

Update Time: 2024-07-01

This template belongs to biology courseware People's Education Edition Biology for Grade 8, Volume 2 industry PPT template

Preview