organisms whose body includes only one cell, are the simplest.They may have different shapes and various modes of transportation.Everyone knows at least one name, which is the simplest living organism, but not all realize that this is such a creature.So, what are they, and what types are most common?And what are these creatures?As complex and coelenterates, single-celled organisms deserve detailed study.
unicellular
Subkingdom Protozoa are tiny creatures.Their bodies are composed of a single cell, which has all the necessary functions for life.So, protists have a metabolism, can be irritability, move and reproduce.Some distinguished permanent form of the body, while others are constantly changing it.The main component of the body is a nucleus surrounded by cytoplasm.In it are several types of organelles.The first - obschekletochnye.These include the ribosome, the mitochondria, the apparatus Galdzhi and the like.Second - special.These include digestive and contractile vacuole.Almost all protists can move around without much difficulty.In doing so, they help pseudopodia, flagella or cilia.A distinctive feature of organisms phagocytosis - the ability to capture particles and digest them.Some may also carry out photosynthesis.
How to extend single-celled?
Protozoa can be found everywhere - in fresh water, the soil or the sea.A high degree of skill to ensure their survival encysted.This means that under adverse conditions, the body falls into a resting stage, covered with a dense protective coating.Create cysts contributes not only to survive, but also the spread - so the body can be in a more comfortable environment, where to get food and the opportunity to reproduce.The body simply carried out recently by a division into two new cells.Some also have the ability to sexual reproduction, there are species that combine both.
Amoeba
It should list the most common organisms.The simplest is often associated with this view - with amoebas.They have constant shape of the body and used for the movement of pseudopodia.They also captures amoeba food - algae, bacteria or other protozoa.Surrounded by her false foot, the body forms a digestive vacuole.Obtained from it all substances into the cytoplasm, and undigested expelled outside.Breathing exercises amoeba whole body by diffusion.Excess water from the body displays the contractile vacuole.The process of reproduction takes place by means of nuclear fission, after which the cells are obtained from one or two.Amoebas are freshwater.There are simple in humans and animals, in this case, they can lead to a variety of diseases or worsen the general condition.
Euglena green
Another body, common in fresh water, also applies to the simplest.In Euglena green body is spindle-shaped with a dense outer layer of cytoplasm.The front end of the body ends with a long flagellum, through which the body moves.In the cytoplasm there are some oval chromatophores, which is chlorophyll.This means that the light is powered euglena autotrophically - is able to not all organisms.Simple guided via eye.If euglena long stay in the dark, chlorophyll disappears and the organism enters a heterotrophic process for supply with absorption of organic substances from water.Like the amoeba, protozoa, these reproduce by dividing, and breathe all over.
Volvox
include unicellular and colonial organisms occur.Simply titled Volvox live that way.They have a spherical shape and gelatinous body formed by individual members of the colony.Each Volvox has two flagella.The coordinated movement of all cells is adapted to move in space.Some of them are able to reproduce.So there are subsidiaries Volvox colony.In the same structure, and different algae, known as Chlamydomonas.
ciliates slipper
This is another common inhabitant of freshwater reservoir.The name ciliates are obliged to form their own cells, reminiscent of the shoe.Organelles used for movement, called cilia.The body has a constant shape with a dense shell and two cores, small and large.The first thing you need to breed, and the second controls all the vital processes.As power ciliate uses bacteria, algae and other single-celled organisms.Just part of the digestive vacuole create, at the shoes she is at a certain location at the mouth.To remove the undigested residues present poroshitsa and selection is carried out with the help of the contractile vacuole.For ciliates characterized by asexual reproduction, but it can be accompanied by the union of two individuals for the exchange of nuclear material.This process is called conjugation.Of all the freshwater protozoa ciliate-slipper is the most complex in its structure.
unicellular soil and seawater
addition to the inhabitants of freshwater reservoir, it is necessary to list other types of protozoa.So, in the sea are the most common organisms radiolarians and foraminifera.Dead bodies of the first form mineral deposits of opals and jasper.Characterized by the presence of foraminifera shells from grains of sand or calcium, and after death to form lime or chalk.And those and others are part of the plankton.The soil is also home to a variety of protozoa.They play a significant role in the formation of a new earth.Further, the organisms may be parasites.They lead to dangerous diseases of humans and animals.The most famous is Plasmodium falciparum, which settles in the blood.Dysentery amoeba can disrupt the colon.Trypanosomes spread sleeping sickness.
