The Importance of Plants:
Plants are autotrophic organisms, meaning that they can produce their own food. These Organisms are of immense importance. Every animal and human are directly and indirectly dependent on plants. These serve other species in many ways.
Plants provide shelter and shade to other organisms and are a source of food for us. Other than that the plants provide the world with oxygen. Oxygen is vital for all living things to survive. Without plants we cannot survive.
What are autotrophic organisms and heterotrophic organisms?
Autotrophic organisms are those species which produce their own food. These species are divided further into 2 groups. The photoautotrophic organisms and the chemoautotrophic organisms. Photoautotrophic (Photo means Light in Greek) organisms produce their own food by the help of light while the Chemoautotrophic organisms produce food by chemical reactions.
The heteroautotophic organisms are dependent on others to supply them with food.
Photosynthesis (Photo meaning light in Greek and Synthesis meaning to construct) is the process in which light energy is converted into chemical energy and synthesize carbohydrates from oxygen and carbon dioxide. The oxygen is given off at the end of the process.
Stages of photosynthesis:
Photosynthesis is done in two stages; The light dependent stage and the dark stage (light independent stage)
The light dependent stage is the first stage in which the light is absorbed by the chlorophyll in the chloroplast to break down the oxygen and carbon dioxide into hydrogen, carbon and oxygen. This is called photolysis.
The stage where the carbon dioxide is reduced to form glucose is called the dark stage. The chemical energy required for this purpose is collected from the light in the light dependent stage. It does not directly require light.
Every leaf is attached to the stem by the petiole. This petiole extends further in to the Lamina and is called mid branch. The mid branch forms vein branches on the lamina.
The lamina is a thin long structure which forms the body of the leaf. It has many vein networks found around the nerve branches. The thin structure of the lamina allows the light and carbon dioxide to enter the leaf easily.
The lamina structure is as follows. The upper region has epidermal cells which are set straight and is covered with cuticle which prevent major water loss. The lower layer is called the misophyll layer which which has two types of cells. The one being the palisade cells. These make the palisade tissue which are found above the xylem and phloem. These are straight structures with lower end curved.
The layer below the palisade tissue is call the spongy mesophyll. These cells are are irregular in shape and have gaps in between them. The lowest layer is called the lower epidermis cells which are just like the upper epidermis cell with cuticle on top. However there is stomata (holes) in this layer. It is protected by the guard cells which are turgid as it has low water potential. The stoma (singular for stomata) allows the oxygen and carbon dioxide to enter the leaf for the Photosynthesis.
The vein consists of the xylem and the phloem. The xylem brings nutrients from the roots to the leaf while phloem takes the produced glucose from the leaf to the rest of the plant.
After photosynthesis the phloem takes the nutrients and carries it across the plant. The cells produces enzymes to break down the food molecule to provide energy. Excess are stored in the storage organs. Most of the energy is used by the growing organs for the growth of the plant.
Plants do not have a digestive system but there is little difference in plant and human digestion techniques.
If you have any questions or have better knowledge please comment. If you liked my article please share it with your friends. Thank You!