Modern science divides all nature into living and nonliving. At first glance, this division may seem simple, but sometimes it’s quite difficult to decide whether a particular object of nature is really alive or not. Everyone knows that the main properties, signs of living things are growth and reproduction. Most scientists use seven life processes or signs of living organisms that distinguish them from inanimate nature.
What is characteristic of all living things
All living things:
- Consist of cells.
- They have different levels of cellular organization. Tissue is a group of cells that perform a common function. Organ - a group of tissues that perform a common function. An organ system is a group of organs that perform a common function. An organism is any living creature in a complex.
- 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.
- Are growing. Cell division is the orderly formation of new cells that grow to a certain size and then divide.
- Propagate. Reproduction does not play a significant role in the survival of individual organisms, but it is important for the survival of the whole 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 combining 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 obvious with animals that can walk and run, and less obvious with 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 a 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 things are able to respond to such stimuli as light, temperature, water, gravity, and so on.
- Height. All living things are growing. A constant increase in the number of cells and body size is called growth.
- Reproduction - the ability to reproduce and transmit genetic information to their offspring.
- Excretion - disposal of waste and toxins. As a result of many chemical reactions taking place in the cells, it is necessary to get rid of metabolic products that can poison the cells.
- Nutrition - the consumption and use of nutrients (proteins, carbohydrates and fats), necessary for growth, tissue repair and energy. Different types of living things do this differently.
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, which are considered the building blocks of life. Cells are amazing, despite their small size, they can work together to form large body structures such 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 up of just one cell, such as many bacteria, while others are made up of trillions of cells, such as humans. Multicellular organisms are very complex creatures with incredible cellular organization. This organization begins its journey with DNA and extends throughout the body.
Breeding
The main signs of living things (biology describes this even in a school course) include also such a thing as reproduction. How do all living organisms get to earth? They appear not from the air, but by reproduction. There are two main ways of producing offspring. The first is sexual reproduction known to all. This is when 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 a gamete. Unlike sexual reproduction, where the offspring has a different genetic composition, not the same as that of any of the parents, the asexual method produces offspring that are genetically identical to its parent.
Growth and development
The main signs of living also suggest growth and development. When offspring is born, it does not remain so forever. A great example can be the person himself. In the process of growth, people change, and the more time passes, the stronger these differences are noticeable. If we compare the adult and the baby with 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 to large. For example, all organs of a living organism grow with age: fingers, eyes, heart, and so on. Development implies the possibility of change or transformation. This process begins even before birth, when the first cell appears.
Energy
Growth, development, cellular processes, and even reproduction can occur only if living organisms accept and can use energy, which is also one of the main signs of a living being. All life 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 into chemical energy is called photosynthesis, and the organisms that can produce it are called autotrophs. However, many organisms cannot create their own food on their own, and therefore they have to feed on other living organisms to obtain energy and nutrients. Organisms that feed on other organisms are called heterotrophs.
Responsiveness
When listing the main signs of wildlife, it is important to note the fact that all living organisms have the ability to respond in a certain way to various environmental stimuli. This means that any changes in the environment trigger certain reactions in the body. For example, a carnivorous plant such as a venus flytrap will slam its bloodthirsty petals quite quickly if an unsuspecting fly lands there. If there is such an opportunity, the turtle will go out to bask in the sun, and will not remain in the shade. When a person hears rumbling in his stomach, he will go to the refrigerator to make a sandwich, and so on.
Irritants can be external (outside the human body) or internal (inside the body), and they help living organisms maintain balance. They are presented in the form of various sensory organs in the body, such as: vision, taste, smell and touch. Response rates may vary by organism.
Homeostasis
The main signs of living organisms include the regulation of the internal environment of the body, which is called homeostasis. For example, temperature regulation is very important for all living things, 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 things 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 have all of the above characteristics.