Many scientists believe that plants first developed in the form of green algae around the Paleozoic era, which was more than 500 million years ago. Just like humans and animals, plants have now evolved, developed, and branched out into thousands of different species. Plants are very unique living things that have a complex cellular system. Unlike humans and other animals, plants have the ability to create and consume their own food. Animals, on the other hand, must either forage for food or hunt and gather food to feed themselves and their offspring. So why do plants operate differently? This is because plants have enclosed nuclei and also go through a process called photosynthesis. This process creates something called chlorophyll, which is a form of carbohydrate that the plant can then convert into food and energy. The combination of water and carbon dioxide is needed to create the chlorophyll; plants need water to survive as well. All that is needed for a plant to make chlorophyll is for it to exist in an area where the needed elements are present. The plant's cells do the rest of the work.
Animals must consume protein in order to obtain nitrogen, but this is not the case for plants. Instead, they must have a good amount of water and sunlight in order to help them begin the process of photosynthesis. Plants also retrieve nutrients from the soil, which their cells then harvest and use for nourishment. This process of photosynthesis helps bring nutrients to the cells, helps the plant grow, and keeps the cell structures in working order. The nutrients that plants get include carbon, magnesium, nitrogen, calcium, and potassium, among others. These nutrients are known as macroelements. Plants also obtain nutrients known as microelements, which include copper, iron, chlorine, and zinc. They only need smaller amounts of these macroelements to survive, but they are still essential for a healthy plant to grow and thrive.
The cell wall of a plant is very rigid and surrounds a plasma membrane. This cell wall protects the interior plasma membrane and helps the plant to grow. The ability of a plant to go through the process of photosynthesis in part thanks to chloroplasts. These parts of the cell help the plant to make its own energy. Animals do not have chloroplasts; these are only found in plant life. Another integral element of plant cells is the endoplasmic reticulum, a group of tiny sacs that help create and then transport chemical compounds both in and outside of the plant's cells. Lysosomes are other sacs in the plant cell that serve as the digestive system. These tiny cell elements break down the macroelements and prevent buildup from occurring with the cell.
The golgi apparatus helps to take the elements from the endoplasmic reticulum and helps to modify proteins and fats for use outside of the cell. All plants and living things have an element of the cell called a plasma membrane. This membrane holds all of the contents of the cells inside a tough cell wall. Other elements of plant cells include ribosomes, which are tiny organelles that consist of approximately 60 percent RNA and 40 percent protein. Plant cells have many other important elements, including a vacuole, which helps with the structure and growth of the plant; the nucleus, basically the hub of all activity for all cells; and microfilaments, which contribute to the exterior structure and skeleton of the plant. Plants have a complex system of cellular activity that is constantly occurring inside of them. These tiny cell parts all work together in synergy to help make sure that the plant is functioning properly, is protected, and is being fed, receiving all of the nutrients it needs to survive.
For more information on plant cells and their structures, refer to the following websites:
- Plant Cells Basics
- Plant Cell Illustration
- More About Plant Cell Walls
- Basic Elements of the Plant Cell
- Plant Cell Characteristics
- Plant Cells, Tissues, and Tissue Systems
- Inside a Cell (interactive)
- Discover More About Each Element of a Plant Cell
- Plant Structures: Cells, Tissues, and Structures
- Plant Cells: Plastids
- Investigating Plant Cells, Tissues, and Primary Growth
- Flowers Celebrating Birth and Growth
- Plant Anatomy Glossary
- Virtual Lab: How to Plant and Animal Cells Work
- Plant Cell Imaging: Carnegie Institute for Science
- Animal Cell vs. Plant Cell: Comparison Chart
This article was posted by Chad Kremp
