Animal cells and plant cells are two types of eukaryotic cells, but they differ significantly in structure and function. Understanding these differences is crucial for a deeper understanding of biology and cell function. In this article, we will explore the unique structures and functions that animal cells possess but plant cells lack , helping readers better understand the evolutionary and biological specificities of these two cell types.
1. Centrosome
One of the most significant differences lies in the presence of centrosomes . Animal cells contain structures called centrosomes , which consist of two centrioles located near the nucleus. Centrosomes play a crucial role in cell division, helping to form the spindle apparatus and ensuring that chromosomes are evenly distributed to the two daughter cells during mitosis or meiosis.
Animal cells include: centrosomes
Plant cells lack: centrosome
Plant cells do not have centrosomes, but they can still form spindles during cell division, usually through other microtubule tissue centers.
2. Lysosome
Lysosomes are organelles unique to animal cells. They are small vesicles enclosed by a single membrane and filled with hydrolytic enzymes. The main functions of lysosomes are to break down and recycle cellular waste, including digesting foreign substances (such as bacteria), cleaning damaged organelles, and helping to maintain normal cellular function through intracellular digestion.
Animal cells include: lysosomes
Plant cells lack: typical lysosomes
Although plant cells also have structures similar to lysosomes, such as vacuoles which can participate in some decomposition functions, their functions are not exactly the same as those of lysosomes.
3. Intermediate Fibers
The cytoskeleton of animal cells is composed of microtubules, microfilaments, and intermediate filaments. Among them, intermediate filaments are mainly responsible for enhancing the mechanical strength of cells and maintaining the stability of cell structure, especially when subjected to external pressure or tension.
Animal cells contain: intermediate fibrous tissue
Plant cells lack: intermediate fibers
Although plant cells also have a cytoskeleton, they lack the intermediate filaments. The rigidity of plant cells mainly depends on the cell wall, rather than on intermediate filaments like animal cells.
4. Tight junctions and desmosomes
Animal cells possess unique cell-connecting structures that help cells bind tightly together, forming tissues and controlling the flow of substances between cells. Tight junctions and desmosomes are two of the main types of cell-connecting structures.
Tight junctions : form a barrier in epithelial tissue to prevent molecules from passing through intercellular spaces.
Desmosomes : Through strong connections between cells, they ensure the overall structure and strength of tissues.
Animal cells contain: tight junctions and desmosomes.
Plant cells lack: tight junctions and desmosomes
Plant cells communicate and transfer substances through plasmodesmata, replacing tight junctions and desmosomes in animal cells.
5. Glycogen Granules
Animal cells primarily store energy in the form of glycogen . Glycogen is a polysaccharide that is stored as granules in animal cells for use when energy is needed. Animal cells contain a large number of glycogen granules, especially in liver and muscle cells.
Animal cells contain: glycogen granules
Plant cells lack: glycogen granules
Plant cells store energy through starch. While both are functionally similar, glycogen and starch are different molecules.
6. Microvilli
In some animal cells, especially epithelial cells, there are microvilli on the cell surface, which are tiny outward projections of the cell membrane. These structures greatly increase the cell's surface area, and microvilli can improve the cell's functional efficiency, especially when absorbing nutrients or expelling waste (such as in intestinal cells).
Animal cells include: microvilli (some cells).
Plant cells lack: microvilli
Plant cells generally do not have such a structure; they rely on the properties of the cell wall and vacuoles to regulate internal pressure in order to maintain their shape and function.
Despite their many similarities, animal and plant cells differ significantly in structure and function. The unique structures of animal cells (such as centrosomes, lysosomes, and intermediate filaments) enable them to perform functions distinct from those of plant cells, particularly in areas like movement, energy storage, intercellular connections, and cell division. Understanding these differences not only helps us better comprehend cell biology but also deepens our understanding of the unique characteristics of various biological systems during evolution.
