The structural level of plants is: cells → tissues → organs → plants. The detailed process is: cells divide first to increase the number of cells, then differentiate into tissues, and then tissues form organs, and multiple organs are combined in a certain order to form plants. So, what is the structure of the cells that make up plants?
(1) Thin and brittle wall with protection and support.
② Cell membrane can control the entry and exit of substances.
(3) Chloroplast, where plants carry out photosynthesis.
④ The nucleus contains genetic material.
⑤ Vacuole, cell fluid containing nutrients.
⑥ Cytoplasm, the site of life activities.
The structure of plant cells consists of cell wall, cell membrane, cytoplasm and nucleus. Plant cells also have chloroplasts and mitochondria. However, it should be noted that not all plant cells have chloroplasts, for example, the epidermal cells of onion scales have no chloroplasts.
Let's start with animal cells. The structural level of animal body: cell → tissue → organ → system → animal body. The structural levels of animals are more than those of plants, but the cell structures of animals and plants are quite different.
① Cell membrane can control the entry and exit of substances.
② The nucleus contains genetic material.
③ Cytoplasm, the site of life activities.
Animal cells have no cell walls and usually no vacuoles.
Now, the difference of cell structure between animals and plants is clear at a glance.
Although plant cells or various cells of animals have different shapes, their basic structures are the same. They all have cell membrane, cytoplasm and nucleus. Like animal cells, the cytoplasm of plant cells also contains mitochondria. But animal cells have no cell walls, chloroplasts and usually no vacuoles.