"Plant Leaves and Transpiration" PPT

Description

"Plant Leaves and Transpiration" PPT

Part One: Structure of Blades

leaf structure

blade

Petiole: It is the channel through which the stem transports water and inorganic salts to the leaves.

The structure of the blade

upper and lower epidermis

Epidermal cells: colorless, transparent, irregular shape

Guard cells: half-moon shape. Contains chloroplasts, which appear in pairs to form stomata.

Stomata: consists of two guard cells. Guard cells absorb water and swell, opening the stomata; losing water, the stomata close. The stomata are the channels through which water in leaves transpire, and are the gateways for gases such as oxygen and carbon dioxide to enter and exit.

Mesophyll mesophyll cells contain a large number of chloroplasts, whose main function is to carry out photosynthesis

Leaf veins are distributed in the mesophyll and play a supporting role. Contains conductive tissue, responsible for transporting water, inorganic salts, and organic matter.

Plant leaves and transpiration PPT, part 2 content: Transpiration

The process in which water absorbed by plant roots is emitted from the plant body to the outside of the body in a gaseous state is called transpiration.

About 99% of the water absorbed by the roots is emitted through transpiration.

Discuss the significance of transpiration

① Reduce the temperature of the plant body (leaves)

②Promote roots to absorb water and inorganic salts

③Promote the transportation of water and inorganic salts in plants

———Is an important source of power for water absorption and transportation

The relationship between transpiration and environmental factors

Generally, if the area around the stomata

If the humidity is high, the temperature is low, and the light is weak, the transpiration will be weak;

If the humidity is low, the temperature is high, and the light is strong, the transpiration will be strong.

Practical applications of transpiration

When transplanting plants, it is necessary to prevent the plants from dying due to lack of water and reducing the survival rate.

think

When we transplant plants, how do you think we can improve the survival rate?

1. Transplant with soil and water to enhance water absorption function

2. Cut off some branches and leaves, shade them from the sun, and try to transplant them in the evening to reduce transpiration and prevent the plants from losing water and dying.

Keywords: Zhejiang Education Edition eighth grade science PPT courseware for the second volume free download, plant leaves and transpiration PPT download, .PPT format;

For more information about the PPT courseware "Leaves of Plants and Transpiration", please click the "Leaves of Plants and Transpiration" ppt tag.

"Plant Leaves and Transpiration" PPT courseware:

"Plant Leaves and Transpiration" PPT courseware Part One: Leaf Structure Although the shapes of leaves are diverse, their basic structures are similar. A leaf is composed of petiole and blade, and blade is composed of epidermis, mesophyll and veins. ..

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Update Time: 2024-10-20

This template belongs to science courseware Zhejiang Education Edition Eighth Grade Science Volume 2 industry PPT template

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