There are more than 7000 types of ciliates, but the most famous of them is the ciliate shoe. All of these unicellular organisms are covered with cilia. Most of them live in salt or fresh water, but some species settle in the stomach of ruminant mammals, thereby facilitating the digestion of fiber.
Instructions
Step 1
Infusoria-shoe is a fast-swimming protozoan with a length of 0.1-0.3 mm. She lives in reservoirs with polluted water, and her body, covered with longitudinal rows of short cilia, resembles a small shoe. Due to the dense outer layer of the cytoplasm, the ciliate retains a constant shape.
Step 2
Numerous cilia of ciliates are similar in structure to the flagella of green euglena and volvox. With the help of their wave-like movements, the shoe moves in the water column with its front end forward.
Step 3
Single-celled animals that move with the help of cilia are classified as ciliates. For the first time, such protozoa were found in water infused with herbs. The word "infusum" itself, from which the name ciliates comes from, means "tincture".
Step 4
From the front end of the body to the middle of the shoe, it has a groove with longer cilia. At its posterior end, there is a mouth opening, which continues with a tubular pharynx. The cilia of the groove move continuously, "driving" water and food particles to the animal's mouth. The main food of ciliates is bacteria.
Step 5
In the cytoplasm of the shoe, a digestive vacuole is formed around the bacteria, which digests the food particle by releasing digestive juice into it. Like other protozoa, for example, amoeba, the cytoplasm of the ciliate is in constant motion.
Step 6
With the current of the cytoplasm, the digestive vacuole, breaking away from the pharynx, spreads through the body of the ciliate shoe, contributing to the uniform absorption of nutrients. Undigested food debris goes out through the powder of the unicellular.
Step 7
The release of harmful metabolic products in ciliates occurs with the help of two contractile vacuoles. One of them is located in the front, the other in the back. Alternately contracting with an interval of 20-25 seconds, they eject excess water with unnecessary substances, which are collected in the vacuole of the shoe along the adductor tubules.
Step 8
In the cytoplasm of the simplest, there are two nuclei - small and large. The main role in reproduction is assigned to the small nucleus, and the large one regulates the processes of nutrition, excretion and movement.
Step 9
The ciliate reproduces, like the amoeba, by dividing the body in two. Moreover, first the small nucleus divides, then the large one, and only then the cytoplasm is pulled over. In each of the two young shoes, one contractile vacuole remains, and the second vacuole and the tubule system grow anew. Young ciliates feed and grow, and after a day the division is repeated.
Step 10
Ciliates have primitive irritability. This can be traced in experiments with the addition of a salt crystal and an infusion with bacteria to the water. In the first case, the animals will try to swim away from the saline solution that is harmful to them, in the second, on the contrary, they will gather around their favorite food.
