Why plant cells are more totipotent than animal cells

Plant cells and animal cells.

Plant cells are diverse, such as unicellular algae are often spherical, the cells of higher plant transport tissues are long cylindrical, the cells (fibers) supporting tissues are long spindle-shaped, the leaf surface cells are flattened, and the parenchyma cells are polyhedra.

Plant cells are composed of parts such as cell wall, cell membrane, cytoplasm and nucleus, and the cell wall is an inanimate substance. Except for the cell wall, the rest is called a protoplast. Taking onion epidermal cells as an example, there is a thin layer of colorless and transparent wall on the outside, called the cell wall, which is unique to plant cells and has a protective and supportive effect.

The gelatinous substance that binds adjacent cell walls together is called the intercellular layer. The cell membrane is a thin film that is tightly attached to the cell wall, also called the plasma membrane, which is generally not visible under the light microscope, and can only be seen when doing plasma wall separation experiments, which can control the exchange of substances inside and outside the cell. Cytoplasm is a colorless and transparent viscous liquid outside the nucleus in the plasma membrane, which is generally dyed pale yellow by dropping potassium iodide solution when observed under light microscopy, and is close to the cell wall into a thin layer in mature cells.

Some cells can see plastids in the cytoplasm, which are organelles unique to plant cells, such as chloroplasts. The nucleus is a colorless, transparent, refractive oval sphere that is yellow after staining and surrounded by a nuclear membrane. There are one or several small spherical, refractive nucleoli in the nucleus, and the protoplasm outside the nucleolus and within the nuclear membrane is called nucleoplasm.

The nucleus contains substances that play a significant role in genetically. Vacuoles are vacuole-shaped and dispersed in the cytoplasm into several or joined to form a large intermediate vacuole.

Animal cells are also diverse. Free cells are mostly round or oval in shape, such as blood cells and eggs. Tightly connected cells are flat, columnar, etc., such as hepatocytes and epithelial cells, and muscle cells are mostly spindle-shaped. Nerve cells are star-shaped and have long protrusions.

Artinations are also made up of a cell membrane, cytoplasm, and nucleus, but do not have a cell wall.

Most plant cells are between 25 and 50 microns in diameter. Very few large cells are visible to the naked eye, such as cotton cells up to 75 mm long and ramie stems up to 550 mm long fibers. Animal cells are generally small, but there are a few exceptions, such as some bird eggs (excluding egg whites) that can be up to a few centimeters in diameter.

Both plant cells and animal cells are totipotent and can actually develop into complete individuals. (This can be demonstrated by monoclonal antibody technology in animals as well as somatic cell cloning) However, due to the high degree of differentiation of animals, it is generally only considered that their nuclei are totipotent.

Because animals are highly differentiated in order to achieve higher evolution, they lose their totipotency. Plant cells, on the other hand, are lower and can differentiate backwards.

Because of the high degree of differentiation of animal cells, the totipotency is limited, and the nucleus of animal cells has totipotency.

In general, the level of cell totipotency is related to the degree of cell differentiation, and the higher the degree of differentiation, the lower the cell totipotency.

I think it's probably because plants don't have a complex and huge nervous system.

Because plant cells have cell walls, chloroplasts, vacuoles.

There are basically three definitions of totipotency.

One is that "differentiated cells have the potential to redevelop into complete individuals", which excludes zygotes, but in fact there is now a consensus that zygotes are the most totipotent;

One argument is that "a cell contains all the genetic information of the organism and can develop into a complete organism under the right conditions", which strictly excludes in ex vivo culture of anthers or the development of egg cells into individuals (doubtful);

In 1984, the International Organization Culture Association made a definition, "Cell totipotency is a certain characteristic of the cell, and the cell with this ability retains the ability to form all cell types of the organism", this definition includes the differentiation and development of fertilized eggs, anthers, and egg cells, as well as the production of secondary metabolites by cultured cells (such as the production of paclitaxel by yew cell culture).

According to the first two statements, animal cells are not totipotent, if according to the third statement, animal cells are totipotent.