The Vital functions of living things (People, animals and plants) are the function of nutrition , The relation function and the reproduction function.
Living beings form a complex organization, endowed with a molecular communication system, capable of developing the basic functions of life, which are nutrition, relationship and reproduction.
They are composed to 95% by four bioelements; Carbon, hydrogen, oxygen and nitrogen. These bioelements form biomolecules, which can be organic or inorganic. In addition, they consist of Cells . These produce chemical reactions that are the basis of the functioning of living beings.
Depending on the number of cells we can divide living beings into two large groups, unicellular and multicellular. The unicellular organisms are organisms composed of a single cell, such as bacteria or protozoa. They are the most primitive living beings, because they are less complex. On the planet there are more single-celled organisms than multicellular organisms.
Multicellular organisms are those formed by more than one cell. These have not always been as we know them today, but have evolved over time.
The theory of the evolution of Darwin , Of 1859, postulated in his book The origin of species , Argues that living beings adapt to their environment by developing characteristics for survival.
Living beings that fail to adapt eventually perish. Only the strongest survive and eventually develop the characteristics and functions necessary for life and survival. This is known as natural selection.
Functions of living beings
For living beings to stay alive, they need to perform their vital functions. These are nutrition, relationship and reproduction.
Nutrition
Through nutrition, living things acquire nutrients that are converted into energy to perform the rest of vital functions.
In order to perform the nutrition process, one begins with the intake of substances, many of these are not absorbed as such, but need to go through a digestion process, which transforms them into substances that can be used by the cells.
Within each living being produce chemical reactions and that allow to obtain the energy and materials necessary for life. This is called metabolism, and can be catabolism or anabolism.
Finally, to end the nutrition process, excretion occurs. Living things expel waste substances that the body can not absorb.
The nutrition function is the most important for living things to survive, because it provides the energy necessary for the body to function.
Relationship
Living beings have the ability to relate to their environment. The relation of living beings to each other, ends up forming an ecosystem. It is impossible for a living being to survive isolated from its environment. There are several types of relationships between living beings, the most important being neutralism, mutualism, facilitation, predation and parasitism.
Neutralism is that relationship in which the interaction of two species neither benefits nor harms the other, as opposed to mutualism, which is the interaction of two species in which both benefit. Facilitation is the interaction of several species of living beings where at least one of them is facilitated by the relationship between all.
Predation is the interaction where one living thing feeds on another, usually a predator that catches a prey and uses it as food. Finally, parasitism, where the host species is harmed by the organism that inhabits it, usually a parasite.
Reproduction
It is the function by which the alive beings can create another life with characteristics similar to the progenitors. It is the necessary function for the survival of the species and to create organisms with similar characteristics. Reproduction can be of two types, asexual or sexual.
The asexual reproduction Is one in which an organism is capable of creating another by itself. The resulting living being is a copy of the parent, since it does not obtain DNA exchange from another parent.
A clear example of asexual reproduction is that produced with bacteria, where a bacterium can be divided into two totally identical bacteria and with the same genetic load.
The Sexual reproduction Is one in which two living beings of different sexes intervene. The resulting living beings or descendants, will have a genetic composition of the DNA of the parents, so they will not be the same, but do share genetic characteristics.
It is the most common form of reproduction among multicellular beings, where two cells unite in fertilization to generate a new life.
Fundamental Characteristics of Living Things
All living things have common characteristics that define them as living beings. The characteristics of living things develop in their life cycle and are closely related to the vital functions described. These characteristics are:
Be born
All living beings come from another organism from which they copy their cellular composition. It is the moment of the beginning of the life of the living being. In the case of viviparous beings, such as humans and mammals, they are born the moment they leave the womb.
In the case of the oviparous beings, like birds and reptiles, they are born of an egg. Plants, for example, are considered to be born the moment they come out of their seed.
Feeding
Living things need to be nourished in order to get energy and develop. The chemical reactions that occur at the time of food intake provide the necessary nutrients for the development of the activities of living organisms.
Grow
All living beings have to develop throughout their life. When they are born they are small organisms. In the case of humans, for example, individuals need to grow and develop before they can perform the basic functions of living beings on their own and without the help of their environment.
Be related
Living beings develop with their environment, capture what happens around them and interact with it.
Reproduction
Living beings can in turn form new living beings with their same characteristics, through reproduction.
Aging and dying
The characteristic of aging is distinguished from that of growth because the latter is produced to reach the maturity of the living being. Once the maturity arrives, the cells begin to deteriorate until the living being reaches the end of its life with death.
Classification of living things
The forms of life that we can find in our environment are divided into realms. Living things are normally grouped into five groups.
animal Kingdom
This kingdom is made up of animals. They have a nervous system and senses, and can react to the stimuli they encounter. Biologically, these living beings have eukaryotic cells, meaning that their cells form tissues and have differentiated nuclei. They are Heterotrophic beings , Which means that they feed on other living things.
They can also be divided into vertebrates and invertebrates. Vertebrates are those that have a spine and have a locomotor device that allows you to move. This group includes mammals, birds, fish, reptiles and amphibians.
Invertebrates do not have bones, although they may have some hard parts, such as shells or exoskeletons. The group of invertebrates is composed of arthropods, echinoderms, worms, mollusks, coelenterates and Poriferous .
vegetal kingdom
As its name says, it is made up of plants. These are the only autotrophic beings, that is, the only ones that can produce their own food. They can not move or have organs.
Kingdom of the mushrooms
They are living beings halfway between plants and animals. Like plants, they can not move or have organs, and like animals, they feed on other living things. Fundamentally, their food consists of poor food, decaying animals, etc.
Protoctista kingdom
Formed by eukaryotic cells, they are divided into protozoa and red and brown algae.
Monarch kingdom
This kingdom is formed by the bacteria that populate the planet.
References
- GRIFFIN, Diane E.; OLDSTONE, Michael BA (ed.) Measles: history and basic biology . Springer Science & Business Media, 2008.
- NAGLE, Raymond B. Intermediate filaments: a review of the basic biology. The American journal of surgical pathology , 1987, vol. 12, p. 4-16.
- PARKER, Sybil P. Synopsis and classification of living organisms.
- DARWIN, Charles. On the origin of species by means of natural selection. London: Murray Google Scholar , 1968.
- MATURANA-ROMESÍN, Humberto; Pp. The origin of species by means of natural drift. Chilean journal of natural history , 2000, vol. 73, no. 2, p. 261-310.
- SCHLUTER, Dolph. Ecology and the origin of species. Trends in ecology & evolution , 2001, vol. 16, no. 7, p. 372-380.
- MACARTHUR, Robert H. Patterns of species diversity. Biological reviews , 1965, vol. 40, no. 4, p. 510-533.