The ciliates are a fairly common species, which belong to the group of simple organisms. It lives in fresh standing water bodies with a sufficient amount of organic materials, which it feeds on. By the way, the structure of the ciliates is considered the most complex of this group of organisms.
general characteristics
An infusorian shoe is a unicellular organism whose shape really resembles the sole of a shoe and is maintained by the dense outer layer of the cytoplasm. The whole body of the animal is covered with a huge number of cilia, which are located in longitudinal rows. Their main function is movement.
The ciliates shoe moves with a blunt end forward. Cilia move with a slight delay relative to each other. When moving, the body also rotates around an axis.
Between the cilia are the so-called trichocysts - small spindle-shaped organelles that serve as a defense. Each trichocyst consists of a body and a tip, which, in the presence of an irritant (collision, heating, cooling), shoot sharply.
Ciliates shoe: structure
The bulk of the body is the endoplasm, or the liquid part of the cytoplasm. Ectoplasm is closer to the cytoplasmic membrane, has a more dense texture and forms a pellicle.
Digestion. The ciliates shoe feeds on bacteria and has a rather peculiar cellular digestive system. Closer to the front end of the body is a near-mouth funnel, the inner surface of which is covered with a complex system of cilia. The movements of the cilia create a flow, along with which microorganisms are sucked in. Further, the nutrient particles enter the pharynx, which is also lined with cilia, and only then - in the mouth. Through endocytosis, nutrients enter the digestive vacuole. Residues are removed through a specific organelle - powder.
Genetic material. The ciliates shoe has two cores - large (macronucleus) and small (micronucleus). The micronucleus contains a complete set of genetic information and takes part in the sexual reproduction of the body. The macronucleus is responsible for the synthesis of protein compounds.
Isolation and respiration. An infusoria shoe is able to exist even at very low concentrations of oxygen in the water. Oxygen is absorbed by the entire surface.
As already mentioned, this simplest organism lives in fresh water and, due to the difference in concentrations, it needs an osmoregulation system. The infusoria has two contractile vacuoles - anterior and posterior, to each of which an extensive system of tubules leads. Excess fluid and secondary metabolic products are collected in the tubules and vacuoles are released into the environment. Both organelles contract alternately, every 15–20 seconds.
Reproduction of ciliates
This organism is characterized by both sexual and asexual reproduction.
Asexual reproduction is carried out by transverse division of the cell into two equal parts. In this case, the body remains active. The following are quite complex regeneration processes, during which each part of the body completes the necessary organelles.
Sexual relations between two individuals are carried out by conjugation. Ciliates are temporarily glued, and a peculiar bridge of cytoplasm forms between their surfaces. The macronuclei of both organisms are destroyed, and small nuclei divide by meiosis.
The field of this is formed by four nuclei with a haploid set of chromosomes. Then three of them die, and the remaining share by mitosis, forming two protonuclei - female and male. Organisms exchange "male" protonuclei. Then in each there is a fusion of two nuclei and the formation of a syncaryaon. Then mitosis passes, after which one of the formed nuclei becomes a macronucleus, and the second a micronucleus.