Today in the world there are over 100 thousand species of animals and plants that live on our planet with us. Many of them play a crucial role in the biological food chain, without which existing biogenesis is unthinkable. For the convenience of studying the plant and animal kingdoms, scientists from all over the world have long brought all known living organisms into a certain classification, combining them according to common biological characteristics. In determining any animal, insect or plant for one species or another, the main role is played by homologous organs, which are the same structure of various organs in animals and birds.
So, for example, the wings and plumage are homologous organs in all birds, four limbs in all animals, leaves and flowers in plants, and so on. Thanks to this, we all share the animals, birds, plants and fish known to us into certain groups and species. It is noteworthy that each species has its own both similar and different traits, which are basic when comparing them with other living organisms.
Homologous organs are the most important species characteristics of a particular kind of organism, which also allow the animal to live in a particular environment. So, all fish living in fresh water bodies and lakes have a scaly surface, which acts as a protective spacesuit that allows fish to be invisible in water, easily escape from pursuit, and protect themselves from possible attacks from other species. The same homologous organs in all fish on the planet are the tail and fins, thanks to which the fish can swim in the water.
The very concept of homologous organs comes from the Latin word "homos", which means "identical." That is, these are organs that have the same structure, as well as a similar location in the body of animals or plants. However, this similarity does not allow us to talk about their identical functions, since they just can be completely different. As an example, we can give the same structure of the skeletal system of the forelimbs in all animals and birds. However, animals use them for movement on land, and birds for flight, although if you disassemble their internal structure, it will have very similar characteristics.
If we talk about the kingdom of plants, then their homologous organs are represented by petals, stamens, stem, root system and fruits. Any plant has a thread-branched root, which exists in order to keep the plant on the ground, and also receive nutrition from ash, mineral and organic substances in the soil. Lamellar leaves of plants are used to assimilate carbon and evaporate moisture, and a long elongated stem is needed in order to bring assimilating flowers and leaves to the surface to light and air for better pollination and propagation of the plant.
Scientists discovered the homologous organs of plants in ancient times, and when compiling their scientific works, many philosophers cited the example of the life of the kingdom of animals and plants as the basis for the harmonious existence of all biological creatures on our planet. It should also be understood that in the course of their evolutionary development, many plants and animals underwent a certain transformation, as a result of which some organs lost their value and atrophied, while others, on the contrary, developed, gained strength and took the main role in the life of a living creature. Thus, scientists once again became convinced of the truth of a simple biological truth - if an organ is not used, then it gradually dies, allowing others to develop stronger and better.
Summing up all of the above, we can conclude that homologous organs are the most important organs of biological creatures that have the same morphological significance, but can perform completely different functions depending on the type of plants or species of animals. Despite the accumulated knowledge of scientists in this matter, there is still room for further research.