V. Think of possible questions for the following answers

1. Because viruses are not free-living organisms.

2. It’s the extracellular form of a virus;

3. These organisms are called viroids.

4. Because they do not have ribosomes.

5. The virus derives it from the host cell.

6. It performs three basic functions.

7. The reason is in the frequent changes of the viral DNA or RNA sequences.

8. Viruses can reproduce only in host cells.

9. Such viruses do not destroy the cell at once.

10. Short term diseases are referred to as acute and long-term diseases are called chronic.

VI. Say whether the following statements are true or false according to the text “Viruses”

1. Viruses lack some functions characteristics of other living organisms.

2. All viruses have RNA molecules.

3. At different stages of their development virions can transform into viroids or prions.

4. The parasitic nature of viruses is manifested in their dependence on host cells for energy and protein synthesis mechanism.

5. A virus deprived of its capsule can never penetrate into the host cell.

6. The virion capsid performs a protective function.

7. The main criteria used for viruses classification are their size and shape.

8. Viruses lack the mechanism of correcting the errors in the nucleic acid sequences.

9. The viruses are harmless for their host cell as long as the latter are not subjected to specific physical or chemical influences.

10. Medicine of the future may rely on viruses for the repair of certain genetic defects in humans.

VII. Skim the text “Viruses” one more time to find the words with the following meanings

to a large extent or degree;

to pass into or through;

the inner part of a thing : inside;

the amount of specified material contained; proportion;

a natural enclosing covering;

to take something that belongs to someone else forcibly;

marked by moderation; not extreme or excessive; mild;

hurt or damage;

affected in a negative way and suffering as a result of it;

occurring again after an interval.

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<== попередня сторінка	\|	наступна сторінка ==>
Vocabulary notes	\|	VIII. Use the words from the previous exercise to fill in the blanks in the sentences below

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