Plants may be defined as multicellular organisms with photosynthetic organelles. Unlike animals, they can produce their food in the presence of sunlight and carbon dioxide. They are the eukaryotic species belonging to the Kingdom Plantae.
Initially, when the classification of organisms was made, the fungi and algae were all grouped under the category of plants. As per the strict classification now, all the fungi and certain algae, along with prokaryotes like bacteria and archaea, are removed from the classification of plants. Therefore, according to the present classification, the Kingdom Plantae includes flowering species, gymnosperms, and green algae.
Green plants primarily derive their energy from sunlight using which they manufacture food. Plants make carbohydrates from photosynthesis which is the major forms of energy for plants. The green pigment called the chloroplast synthesizes energy by endosymbiosis with cyanobacteria.
The chloroplast is a cell organelle that contains two primary pigments, which are chlorophyll a and chlorophyll b, which renders the ability to the plants to produce their nutrients. Certain plants have lost the ability to produce food because of the absence of chlorophyll. These are mainly myotropic or parasitic. However, they still bear fruits and buds.
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Plants mainly produce new generations by means of sexual reproduction and alternation of generation, but asexual reproduction is also observed in certain kinds. The diversity in plants is massive, counting up to 320000 species, and about 260 to 290 of them produce seeds. The plants are the man in the source of oxygen in the atmosphere. They possess the ability to convert carbon dioxide into oxygen through photosynthesis and release it into the air. The plants maintain the entire ecosystem, and thus, they are of such significant importance. Survival of other species would be impossible in the absence of plants due to the lack of oxygen in the air. Therefore, their presence is indispensable to the survival of other species.
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Below discussed is the importance of plants and how they are beneficial to the planet-
The branch of biology that deals with the study of the plant are known as Botany.
When we study the plant cells, there we shall notice significant differences between the plant cell and animal cell. It is covered by an outermost layer called the cell wall, which is absent in animal cells. The central vacuole is large and water-filled. It occupies the majority of space in the cell. Finally, there is the presence of chloroplast, which is absent in the animal cells. Chloroplast contains chlorophyll which is the photosynthetic pigment.
The cell wall is made of cellulose which provides rigidity and strength to the cell. Hemicellulose and pectin are other components of the cell wall. During cell division, there is a formation of the phragmoplast, which is the precursor of the cell plate. The cell plate marks the division of the cell in the phase called cytokinesis.
The plant cells differentiate into many kinds. For example, the meristematic tissues are actively dividing and produce other cell types.