Modern science divides all nature into a living andlifeless. At first glance, this division may seem simple, but sometimes it is difficult to decide whether a particular object of nature is really alive or not. Everyone knows that the main properties, signs of the living are growth and reproduction. Most scientists use seven vital processes or signs of living organisms that distinguish them from inanimate nature.
What is characteristic of all living beings
All living beings:
- They consist of cells.
- They have different levels of cellular organization.Tissue is a group of cells performing a common function. Organ is a group of tissues performing a common function. The system of organs is a group of organs performing a general function. The organism is any living being in the complex.
- They use the energy of the Earth and the Sun, which they need for life and growth.
- React to the environment. Behavior is a complex set of reactions.
- Grow. Cell division is the orderly formation of new cells that grow to a certain size, and then divide.
- They multiply.Reproduction does not play a significant role for the survival of individual organisms, but it is important for the survival of the entire species. All living things reproduce in one of the following ways: asexual (production of offspring without the use of gametes), sexual (production of offspring by the interconnection of sex cells).
- Adapt and adapt to environmental conditions.
The main signs of living organisms
- Motion.All living things can move and change their position. This is more evident in the case of animals that can walk and run, and less obvious in plants, parts of which can move to track the movement of the sun. Sometimes the movement can be so slow that it is very difficult to see.
- Breathing is a chemical reaction that occurs inside the cell. This is the process of releasing energy from nutrients in all living cells.
- Sensitivity is the ability to detect changes in the environment. All living beings are able to react to such stimuli as light, temperature, water, gravity, and so on.
- Growth. All living things grow. The constant increase in the number of cells and the size of the body is called growth.
- Reproduction is the ability to reproduce and transmit genetic information to one's offspring.
- Excretion - disposal of waste and toxins. As a result of many chemical reactions taking place in cells, it is necessary to get rid of metabolic products that can poison cells.
- Nutrition - consumption and use of nutrientsubstances (proteins, carbohydrates and fats) necessary for growth, tissue repair and energy recovery. In different species of living beings, this happens in different ways.
All living things are made up of cells
What are the main signs of a living organism?The first thing that makes living organisms unique is that they all consist of cells that are considered building blocks of life. Cells are amazing, despite their small size, they can work together, forming such large structures of the body as tissues and organs. Cells are also specialized - for example, liver cells are located in the organ of the same name, and brain cells function only in the head.
Some organisms are made from just onecells, for example, many bacteria, while others consist of trillions of cells, for example, humans. Multicellular organisms are very complex creatures that have an incredible cellular organization. This organization begins its journey with DNA and extends to the entire body.
Reproduction
The main signs of the living (biology describes thiseven in the school course) also include the notion of reproduction. How do all living organisms get to Earth? They do not appear from the air, but from reproduction. There are two main ways of producing offspring. The first is the sexual reproduction known to all. This is when the organisms produce offspring by combining their gametes. People and many animals fall into this category.
Another type of reproduction is asexual:organisms produce offspring without gametes. Unlike sexual reproduction, where the offspring have a different genetic makeup, different from that of any parent, the sexless method gives offspring genetically identical to their parent.
Growth and development
The main signs of the living also suggest growthand development. When the offspring are born, it does not remain so forever. An excellent example can be the person himself. In the process of growth, people change, and the more time passes, the stronger these differences are visible. If you compare an adult and a baby whom he once came to this world, the differences are simply enormous. Organisms grow and develop throughout life, but these two terms (growth and development) do not mean the same thing.
Growth is when the size changes, from small tolarge. For example, with age, grow all the organs of a living organism: fingers, eyes, heart and so on. Development implies the possibility of change or transformation. This process begins before birth, when the first cell appears.
Energy
Growth, development, cellular processes and evenReproduction can occur only if living organisms accept and can use energy, which is also included in the main signs of a living being. All vital energies ultimately come from the sun, and this power gives energy to everything on Earth. Many living organisms, such as plants and some algae, use the sun to produce their own food.
The process of converting sunlight intochemical energy is called photosynthesis, and organisms that can produce it are called autotrophs. However, many organisms can not create their own food, and therefore they have to eat other living organisms to get energy and nutrients. Organisms that feed on other organisms are called heterotrophs.
Responsiveness
Listing the main signs of wildlife, it is importantnote the fact that all living organisms have the ability to react in a certain way to various stimuli of the environment. This means that any changes in the environment trigger certain reactions in the body. For example, such a carnivorous plant, like a venus flytrap, will shut its bloodthirsty petals quickly enough if an unsuspicious fly lands there. If there is such a possibility, the turtle will come out to bask in the sun, and will not remain in the shade. When a person hears a rumbling in his stomach, he will go to the fridge to make a sandwich, and so on.
Irritants can be external (outside the bodyperson) or internal (inside the body), and they help living organisms maintain their balance. They are presented in the form of various sensory organs in the body, such as: sight, taste, smell and touch. The response rate can vary depending on the organism.
Homeostasis
The main signs of living organisms includeself regulation of the internal environment of the body, which is called homeostasis. For example, the regulation of temperature is very important for all living beings, because body temperature affects such an important process as metabolism. When the body becomes too cold, these processes slow down, and the body can die. The opposite happens if the body overheats, the processes accelerate, and all this leads to the same disastrous consequences.
What do living beings have in common?They must have all the basic signs of a living organism. For example, a cloud can grow in size and move from one place to another, but it is not a living organism, since it does not possess all of the characteristics given above.
