Today, the teacher asked us to observe plant cells with a microscope, and then describe the shape characteristics of plant cells. I took out the box under the table, opened the microscope and put the onion slide under the microscope for observation. Plant cells have cell walls and hard outer layers, which can protect cells and maintain their shape; There is a cell membrane that wraps the cytoplasm and can control substances to enter or leave the cell; There is nucleus, the control center of cells, and then genetic information; There is cytoplasm, which is a transparent colloidal substance, and all kinds of physiological activities are carried out here. Cells are the basic unit of most biological structures, and animals and plants are made up of cells. The vegetative organs of plants are roots, stems and leaves, and the reproductive organs are flowers, fruits and seeds. Generally, plant species are identified by the shape of "leaves" attached to stems and branches, so "leaves" are the parts that directly identify plant species.

The roots of plants usually have different lengths because of different species. Usually, the roots of axial roots can penetrate into the soil with long and thick main roots, while the lengths of small roots of fibrous roots are very close. The stem is the main axis of the aboveground part of the plant, from which branches and leaves are divided. There is a growing point at the top of the stem, which can constantly meristem and make the stem taller. Because of the branches and leaves on the stem. The lower root is the channel of material transportation in plants, the hub of water and nutrients transportation, and supports the development of plant branches and leaves. Trunk is called stem in woody tree planting, that is, trunk is also. Wrapping the trunk, the protection is called bark. Bark is also one of the characteristics of identifying plant species, which can usually be divided into smooth, rough, wrinkled, cracked, finely cracked, scaly, flaky and cloud-like. But because of its abstract shape, it is often difficult to distinguish. Leaves are an important part of every plant, which can carry out photosynthesis, just like a small factory of plants, making food for plants. In the process of manufacturing, oxygen will be released, and water will be absorbed and discharged, which makes a great contribution to the temperature and air of the earth. The attachment state of leaves on stems and branches is called leaf order. Generally, there are alternate leaves, opposite leaves and whorled leaves. Since the mid-1970s, people have tried to transfer foreign genes into animals in various ways. If the unique genes in milk components are transferred to mice, the milk secreted by mice will contain milk components after these exogenous genes are recombined in mice. This kind of mouse that obtains foreign gene by artificial method is called transgenic mouse. The core of transgenic animal technology is to transfer the genetic functional unit-gene into animals and make them become a part of animals. The transferred genes can come from the same or different animals, or from plants or microorganisms. In this way, the boundaries between species are broken, and it can be said that animals can cross with plants and microorganisms. However, the current hybridization is at a low level, and only one or two genes are responsible for one or two traits. With the development of science and technology, more and more genetic information can be transmitted at one time, and then the real hybridization between animals and plants can be realized. Scientifically speaking, this will be a great breakthrough. After this lesson, I learned a lot and understood the shape and structure of plant cells.