Lower plants have no seeds, and the growth process is spore production-spore division-seedling-growing plants.
1. Start with seed germination. The germination of any plant seed needs water, air and suitable temperature. However, the seeds of different plants have different requirements for these three conditions during germination.
2. In the process of plant growth, after germination, the radicle first extends into the soil to form the main root, and then the hypocotyl elongates to push the cotyledons and embryos out of the soil surface. The cotyledons of this seedling were unearthed. The main shaft of seedlings under cotyledons extends from hypocotyl;
3. The growth process of plants can be said to be that the seedlings are basically shaped during hardening, and the hardening period of seedlings begins from the sharp decline of seedling growth to the dormancy period of seedlings.
Extended data:
The stages of plant development are often very different. Plants that complete the process from seed germination to vegetative formation and finally achieve flowering and fruiting in a growing season are called annuals (or primary fruiting plants).
Some plants begin to reach flowering stage after vegetative growth for many years, and the vegetative body will die after flowering (such as bamboo). These plants are called perennial primary fruiting plants. Many woody plants have the habit of flowering and fruiting many times. After they blossom and bear fruit every year, the nutrients do not decline. These plants are called fruitful plants.
Plants have six organs: roots, stems, leaves, flowers, fruits and seeds. The stem is the axis of a plant. Erect or crawling in water, with branches on the stem and meristems at the top of the branches for the top to grow. Stems usually differentiate into short nodes and long nodes. Stem has the function of transporting nutrients and water and supporting leaves, flowers and fruits in a certain space. Some stems also have the functions of photosynthesis, nutrition storage and reproduction.
Leaves are one of the vegetative organs of vascular plants. Its function is to synthesize organic matter through photosynthesis, and it has transpiration to provide roots with the power to absorb water and mineral nutrients from the outside. Flowers are unusually short branches with reproductive function. Fruit is mainly used as a medium for spreading seeds. Seeds have the function of reproduction and reproduction, and they also have various structures suitable for reproduction or resistance to adversity, which creates good conditions for the continuation of plant races.
Most solid substances in plants are obtained from the atmosphere. Through a process called photosynthesis, plants use the energy in sunlight to convert carbon dioxide in the atmosphere into simple sugar. These sugars are used as building materials and constitute the main structural components of plants. Plants mainly rely on soil as support and obtain water, nitrogen, phosphorus and other important basic nutrients.
Most plants need oxygen in the atmosphere (for breathing) and oxygen around their roots to grow successfully. However, some special vascular plants, such as mangroves, can make their roots grow in an anoxic environment.
References:
Baidu encyclopedia-plant development