What makes living beings alive

Characteristics of life and principles of biology

What is living there?

What actually is biology? Maybe you've read that biology as that Science of living things is described. But what are actually living beings? Are there rules or criteria that decide who or what a living being is? And what place do the plants take? You will find the answers in the following section.

Properties of the living

Imagine you have a pet and a stuffed animal, both of which are cats. Well, what is the difference between the plush cat and the domestic cat? That's easy, and you can answer it clearly: the domestic cat is a Creature. The two cats are very different and obviously there are featureswhich we can use to clearly determine which of the two cats is alive. First of all, it is noticeable that the house cat move can. She can run, climb, clean, and jump. So it is Move one of the characteristics that distinguish living things from other things. In addition, you will provide the house cat with a bowl of water and food and feed it with treats, whereas the plush cat will not food needs. The stuffed animal doesn't have to either to breathe. nutrition and breathing are therefore also properties that living beings have. We summarize these properties under the term metabolism together. But metabolism and exercise aren't the only crucial traits. Also include irritability and Reproduction to the properties of living beings. Irritability means, for example, that the house cat can perceive the smallest movements and noises and thereby prey on food. A female animal can also carry young and thereby ensure the continued existence of the species. This is known as reproduction. It's easy to say that the plush cat can't keep up. The fifth and final characteristic of the living is this growth. Humans, animals and also plants grow in the course of their lives. Surely there are baby photos of you, and compared to today you look very different in the pictures. In the beginning, the house cat was also a small kitten that had to develop into a full-grown cat.

But what about them plants? That she too to grow, is easy to see, for example in the early bloomers that grow up through the snow after winter. You probably also know that you have to water plants to keep them from withering. Water and minerals are absorbed through the roots. That means the plants have one too metabolism. The Reproduction is done in different ways. But let's take a look at the fruits, for example Apples. Inside the apple are those Seeds. If the apple falls to the ground, the seeds get into the ground and a new apple tree can outgrow it. sunflowers bear their name not only because of their yellow flowers, but for another reason as well. you rotate their flowers always towards the sun. That is, during the day, when the sun wanders across the sky, emotional the flower always faces the sun. This is a targeted one Move of the plant by their irritability is triggered because it reacts to the influencing factor light.

Now you know the five characteristics of living beings (metabolism, movement, irritability, growth / development, reproduction) and know that not only humans and animals, but also plants belong to living beings.

Organizational levels

You will also agree that many living things are very large, especially when compared to the tiny single or multicellular ones. Living beings can only achieve this size because they tissue who take on different tasks. Tissues are made up of many Cells together, which have the same function. The Muscles For example, in your body there is a certain type of tissue, namely Muscle tissue. The skin also consists of several layers of different tissues and forms the largest organ of the body. Organs consist of different, interacting tissues. Plants also have organs such as flowers, leaves and roots. Several organs in turn form Organ systems, in humans and animals, for example Respiratory system, Digestive system or Nervous system. Together these systems form one organism. Cells, tissues, organs, organ systems and organisms are therefore different Organizational levels of the body.

Principles of biology

Since all life on earth has the same origin and some structures and functions have always been of great advantage in the history of development, there are some basic principles in biology, which is found in all living things. One of those principles is that Compartmentalization. Compartmentalization refers to the division of the cells of eukaryotes into membrane-enclosed reaction spaces or compartments. These are mostly surrounded by biomembranes. The first protocells were nothing more than reaction spaces separated from the environment. The presence of closed reaction spaces enables a regulated division of labor within the cell. Another important basic principle of biology is that Surface enlargementwhich is of great importance in many important areas. Communication on membranes often takes place through the exchange of substances. In order to optimize this, membranes, such as the intestinal wall, are corrugated or form protuberances in order to achieve more surface in the same space.

Another basic principle is that Dissemination of information. It takes place on all levels. Communication processes take place both in a cell and between different cells. Examples of communication systems in living things are the nervous system and the endocrine system.