What are the major stages of development of the plant kingdom from its emergence to the present?

Stages of development of the plant kingdom:

1. The age of fungi and algae plants.

For nearly 3 billion years, from 3.5 billion years ago to 400 million years ago (late Silurian period), plants on Earth were only primitive and inferior fungi and algae.

Among them from 3.5 billion to 1.5 billion years are bacteria and cyanobacteria.

The period of monopoly is often referred to as the era of bacteria-cyanobacteria. It was only from 15 billion years ago that eukaryotic algae such as red algae and green algae appeared.

2. The age of ferns.

From 400 million years ago, some green algae evolved into primitive terrestrials.

Vascular plants, i.e. naked ferns. Although they have no true roots and no leaves, they already have vascular tissues in their bodies and can live on land. In the Devonian period more than 300 million years ago.

In the early and middle periods, they experienced about 30 million years of landward expansion and began to diverge in the direction of adapting to various terrestrial environments. In addition, bryophytes.

They also appeared in the Devonian, but they never formed the dominant group of terrestrial vegetation, and they were only one side branch of the evolution of the plant kingdom.

Naked ferns became extinct at the end of the Devonian period, and were replaced by various ferns that evolved from them; to the Permian.

For about 100 million years, they became the protagonists of terrestrial vegetation at that time. Many tall tree-like ferns flourish, such as scales, reeds, seals, etc.

3. The age of gymnosperms.

From the Permian to the early Cretaceous, it lasted about 100 million years. Many ferns did not adapt to the changes in the environment at that time, and most of them became extinct, and the dominant role of terrestrial vegetation was replaced by gymnosperms. The most primitive gymnosperms (protogymnosperms) also evolved from gymnosperms.

Mesozoic. It is the most prosperous period of gymnosperms, so it is called the Mesozoic era as the era of gymnosperms.

Fourth, the era of angiosperms.

They are a group of plants that developed rapidly from the Cretaceous and replaced the dominance of gymnosperms. Until now, angiosperms are still the dominant group with the most species, the most extensive distribution and the strongest adaptability on the earth.

Throughout the occurrence and development of the plant kingdom, it can be seen that the entire plant kingdom has continuously occurred and developed through genetic variation, natural selection (and artificial selection after the emergence of human beings), and along the line from low to high, from simple to complex, from undifferentiated to differentiated, and from aquatic.

to the evolution of terrestrial laws. New species are constantly being created, and species that do not adapt to changes in environmental conditions are dying and extinction, and this long river of plant evolution will never stop and will never end.

--- plants appeared 2.5 billion years ago (Proterozoic), and the earliest plants in the history of the earth belonged to fungi and algae, and then algae were very prosperous.

- It wasn't until 438 million years ago (Silurian period) that green algae broke free from the constraints of the water environment and landed on the earth for the first time, evolving into ferns, adding green to the earth for the first time.

- 360 million years ago (Carboniferous), ferns became extinct and replaced by lycopodiums, cuneiformes, euferns and seed ferns, forming swampy forests.

- The main plants of the Paleozoic era were almost completely extinct 248 million years ago (Triassic), while gymnosperms began to emerge, evolved pollen tubes, and completely broke away from water dependence to form dense forests.

- At the beginning of the Cretaceous period, 140 million years ago, newer and more advanced angiosperms were already diverging from gymnosperms. After entering the Cenozoic Era, ferns declined further, and gymnosperms went downhill. At this time, angiosperms developed faster and differentiated into more types, and by modern times there were more than 90 orders and more than 200 families.

It is the flowering and falling of angiosperms that decorates the Cenozoic earth, which has four distinct seasons, with extraordinary beauty.

The life of an annual herbaceous plant has to go through six stages: seedling stage, vegetative growth stage, flowering stage, seed setting stage, grain maturity stage, and plant wilting stage.

The life of forest fruit trees (perennial woody plants) has to go through five stages: seedling stage, young tree stage, first fruit stage, full fruit stage, and senescence stage.

Four stages: Seed germination – seedling growth – plant flowering – plant fruiting.

Zygote-embryo-seedling-mature plant.

Stages: embryo development (version of zygote - embryo) endosperm right development (fertilization polar nucleus - endosperm) seed germination (seed (embryo) - seedling).

Vegetative growth (growth of rhizomes and leaves).

Reproductive growth (formation of flower buds).

After that, a new offspring can be produced, fertilized eggs, and the above process is repeated.

With the development of modern science and technology, in countless painful lessons, the understanding has undergone a qualitative leap. In the long-term production activities, due to the change of production methods, there is a surplus of the fruits of hunting and gathering, and the domestication and breeding of animals and the cultivation of plants have produced primitive farming. Due to the differences in the conditions of production activities, people found that the fruits of labor obtained from nature were more time-consuming and laborious than the harvesting of breeding and planting, and agriculture became the main production activity of people, and plants became the object of human auxiliary labor.

This phenomenon has gone through a long time. If ancient plants provided living conditions for human beings, then modern plants have not only satisfied human survival. Human beings make use of the rational allocation of resources, speed up the cultivation of plant resources, adjust the diversification of plant species, and give full play to their higher functions and benefits.

This method is used reasonably and to a limited extent to provide abundant material goods for people's daily life. At the same time, increasing biological resources, protecting the diversity of biological species, enabling human beings to obtain the means of production and means of life, and obtaining the resulting spiritual products (including ideologies and concepts) are irreplaceable for human civilization and progress. Human research on basic natural science and applied science are inseparable from the products provided by plants.

Human aesthetics, art, and culture are also inseparable from the forests, trees, and flowers of plants. People's production and living environment requires the participation of plant species, and in this way, it cultivates people's thoughts and sentiments and creates a civilized moral atmosphere. In particular, the semi-public welfare of forest tourism, rest and health care, and the social function of running industries enable the public to come into contact with nature, improve the social environment, enhance people's physical and mental health, and promote social civilization and progress.

Zygote-embryo-seedling-mature plant The last decay period (cessation stage).

From sowing, it goes through the whole stage of seedling, maturity, flowering, senescence, and withering, and the growth cycle of plants is also a cyclical process.

2. Growth stage:

The life of a plant will go through the seedling stage, the growth period, the flowering period, the fruiting period, and the withering stage.

1. Seedling stage:

The seeds germinate at the right temperature and moisture and grow into seedlings, and this period is known as the seedling stage. In the seedling stage, the seed mainly grows its root parts and leaves.

2. Growth period:

After the seedling stage, the plant will grow rapidly under the right temperature, and this period is the growth period, and the stalks, roots and leaves of the plant will develop rapidly.

3. Flowering period:

After the plant has grown, it is the flowering period, and when it blooms, the bees surround the butterfly array, and they arrive to make an important contribution to the plant's fruiting.

4. Fruiting period:

After flowering, with the help of bees and butterflies, the plant is fertilized and small fruits are produced on the treetops.

5. Withering period:

In autumn, when the fruit is ripe and the leaves wither due to the weather, the plants reach the withering stage.

Plants are one of the main forms of life, including trees, shrubs, vines, grasses, ferns, and familiar organisms such as green algae and lichens. It is estimated that about 350,000 species of seed plants, bryophytes, ferns and ferns exist. Most of the energy of green plants is obtained from sunlight through photosynthesis, and temperature, humidity, light, and fresh water are the basic needs of plants for survival.

Seed plants have six major organs: roots, stems, leaves, flowers, fruits, and seeds. Green plants have the ability to photosynthesize - with the help of light energy and chlorophyll, under the catalytic operation of enzymes, water, inorganic salts and carbon dioxide are used for photosynthesis, releasing oxygen, absorbing carbon dioxide, and producing organic matter such as glucose for plant use.

The origin of life is DNA and raw slurry made up of chemicals. Plants began 2.5 billion years ago (Proterozoic), and the earliest plants in the history of the earth belonged to fungi and algae, and then algae flourished for a time. It wasn't until 438 million years ago (Silurian period) that green algae broke free from the constraints of the aquatic environment and landed on the earth for the first time, evolving into naked ferns and ferns.

For the first time, the land is dressed in green.

The primitive single-celled organisms will gradually become the most primitive algae plants, and as the original single cell will gradually evolve into multicellular. The algae in the water gradually evolved to the land, turning into a lower moss. With the movement of the earth's crust, the plants in the sea gradually evolved into ferns.

After that, ferns will gradually evolve into gymnosperms, and then the highest plants will appear, that is, angiosperms.

Algae. In the earliest period of Haojijian, the primitive single-celled organisms will gradually become the most primitive Yuhe algae plants, such as green algae, cyanobacteria, etc., which originated in water and are very dependent on water, and their growth is also inseparable from water. As it evolves, the original single cell will gradually evolve into a multicellular, and the structure of the front cherry will gradually become more numerous and more complex.

Moss. The algae in the water gradually evolved to the land, turning into lower mosses, such as lichens, which are very adaptable to the environment.

Fern. As the earth's crust progressed, some of the oceans would become land, and the plants in the sea would gradually evolve into ferns. At first, it was only an evolved nudibranch, with no leaves or roots, and only lived on land on false roots.

Later, it will evolve into stems, roots and leaves, but it is still inseparable from water for reproduction.

Gymnosperm. Later, due to climate changes and the movement of the earth's crust, a large number of ferns will disappear, and the previous ferns will gradually evolve into gymnosperms, which can completely escape the influence of water and adapt to the growth on land.

Algae, mosses, ferns, angiosperms, keeps. The most primitive and simple plant is algae. Algae were originally unicellular, such as Yiyu or ruined algae, and then evolved into multicellular algae, such as cotton, kelp, seaweed, etc., which are all multicellular algae.

They also differentiate between marine algae and freshwater algae.