3. Answer the following questions on the text in written form.

1. What did Anton van Leeuwenhoek discover in 1675?

2. What does a Paramecium look like and where is it found?

3. What is a Paramecium made up of?

4. How does it move and feed?

5. Where is the food accumulated and how is it changed?

6. How do Paramecia respire?

7. What is the means of excretion?

8. What is called irritability?

9. How does the Paramecium reproduce?

10. What is a cyst?

11. Why are Paramecia important in the life of Nature?

4. Translate a passage into Russian in written form. Text 4 common amoeba

Habitat

Like the Paramecium, the Common Amoeba lives in moist and wet places, mostly in shallow stagnant fresh-water ponds easily warmed by the sun, it moves slowly by means of pseudopodia on the bottom among the decaying debris of plants.

Structure

The simplest animal in the entire phylum of protozoa is the amoeba. It is a tiny blob of mucus, irregular in form, with an oval corpuscle inside. The mucus is protoplasm and the corpuscle is a nucleus. In the living state it is not easy to see much differentiation of the protoplasm of an amoeba, but in stained specimens the important structures are readily visible, The Amoeba is a single-celled animal, like the Paramecium. It has no chlorophyll either.

Locomotion

When you examine an Amoeba under a microscope, you will notice that as it moves parts of its body are pushed out in the direction of the movement forming pseudopodia (false feet). As the pseudopodia are pushed out they become longer and broader, the protoplasm moving towards and into them. The Amoeba moves about as if flowing from one place to another. As it moves, the shape of the Amoeba's body constantly changes. In Greek, the word "amoibe" means "change".

Nutrition

The Amoeba takes in organic matter found in microscopic algae. It does not have to move fast to obtain its food. Its protoplasm slowly surrounds an immobile particle and gradually draws it inside. There, the particle is surrounded by a drop of digestive juice. A food vacuole is formed. The particle is digested, in other words, it is dissolved. Dissolved food is used to build up the body of the Amoeba. As the undigested food remains are pushed out, the food vacuole bursts.

Food can be taken in and the unused remains excreted from any part of the body.

Respiration

The Amoeba respires in the same way as the Paramecium: by absorbing oxygen and excreting carbon dioxide. Respiration is effected (7) by the entire body surface. Since the animal is very small, oxygen, dissolved in water, easily passes into all sections of the protoplasm. The process of carbon dioxide excretion is equally simple.

Excretion

In the protoplasm a light bubble containing a drop of transparent fluid can easily be seen. This is the contractile vacuole. From time to time, the vacuole bursts and the fluid is excreted. Then it appears again, is gradually filled with transparent fluid, and bursts.

That is how the Amoeba excretes, i.e., gets rid of, water and the waste materials dissolved in it.