"Flowers and Fruits of Plants" PPT

Description

Qingdao version of the first volume of science for the fourth grade, the flowers and fruits of plants PPT

Part One: Classification of Flowers

The basic structure of a peach blossom

A flower is mainly composed of sepals, petals, pistils and stamens. Through observation, we can see that there is pollen inside the stamens, and the lower part of the pistil is the ovary.

Complete flowers and incomplete flowers

Complete flower - composed of four parts: sepals, petals, stamens and pistils, such a flower is called a complete flower;

Such as: azalea, peach blossom, cabbage flower, rapeseed flower, etc.

Incomplete flower - a flower that is missing one or more parts is called an incomplete flower.

Such as: pumpkin flowers, poplar flowers.

male flowers, female flowers

Male flowers - flowers with only stamens and no pistils are called male flowers;

Female flowers - Flowers that have only pistils and no stamens are called female flowers.

Unisexual and bisexual flowers

Unisexual flowers - both male and female flowers are unisexual, such as cucumbers, pumpkins, poplars, and willows.

Bisexual flowers - Flowers with both stamens and pistils are called bisexual flowers, such as cabbage, peach, rapeseed, etc.

Flowers and fruits of plants PPT, part 2: observing the stamens of flowers

The stamens include anthers and filaments, and the anthers contain a lot of pollen.

The pistil consists of three parts: stigma, style and ovary. The column is sticky and is easily stained with pollen.

When each part of the flower matures, the perianth expands and the stamens are revealed, which is flowering.

After the plant blooms. The pollen in the stamens will be released from the anthers and land on the stigma of the pistil. This process is called pollination.

There are two ways of pollination: self-pollination and cross-pollination:

Self-pollination is when pollen falls on the stigma of the same flower;

Cross-pollination is when pollen falls onto the stigma of another flower by external forces.

do you know?

1. In spring, there are often bees flying in the orchard. Is this good for the fruit trees?

Answer: Flowers bloom in the orchards in spring. Most of the flowers in the orchard are entomophilous, so they attract bees to collect pollen.

2. If the pistil of a flower is eaten by a pest, will the flower still bear fruit? Why ?

Answer: No. Because the fruit develops from the ovary that constitutes the pistil.

Flowers and fruits of plants PPT, part 3: What is the relationship between angiosperms and humans?

Provide raw materials for clothing fabrics Provide raw materials for clothing fabrics: cotton

Provide vegetables Provide vegetables: greens, radishes, vegetables...

Provide medicinal products Provide medicinal products: ginseng, wolfberry...

Provide fruits Provide fruits: pears, apples, watermelons...

Provide flowers Provide flowers: peonies, roses...

Provide wood Provide wood: camphor, paulownia...

Providing oils Providing oils: peanuts, castor...

Keywords: Qingdao edition fourth grade science PPT courseware free download, plant flowers and fruits PPT download, .PPT format;

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

"Flowers and Fruits of Plants" PPT courseware:

"Flowers and Fruits of Plants" PPT courseware Part One: Structure and Classification of Flowers Do all flowers have these four-part structure? Flower Complete flower: A flower has four parts: sepals, petals, pistils, and stamens. Such as cabbage flowers, peach flowers, broad bean flowers,...

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Update Time: 2024-10-21

This template belongs to science courseware Qingdao Edition Fourth Grade Science Volume 1 industry PPT template

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