3.Translate the 1st passage into Russian.

4.Read the 2d passage and do the tasks a and b.

A. Name three parts of a virus.

1.______________________ 2.________________________ 3._____________________

B. Complete the sentences and translate them.

1. Genes are made of __________________________________________________

2. Genes are __________________________________________________________

3. A protein coat ______________________________________________________

4. An envelope of fats __________________________________________________

5. Viruses may be ______________________________________________________

5.Read the 3d passage. Say if the statements are true or false. Correct the mistakes. Translate the sentences.

1. Viruses spread in different ways.

2. Plant viruses are often spread by vectors.

3. Some viruses of animals are spread by butterflies.

4. Influenza viruses are spread through the food by people when they cough or sneeze.

5. Noroviruses are transmitted by the faecal-oral route, contaminate hands, food and water.

6. Rotavirus is often spread by indirect contact with infected children.

7. Human Immuno-deficiency Virus HIV is transmitted during sexual contact and by the exposure of infected blood.

6.Read the 4th and 5th passages. Answer the questions. Translate the answers.

1. Where have viruses evolved from?

2. What do viral infections cause?

3. What system eliminates viruses?

4. What diseases are caused by viruses?

5. What drugs can help to treat viral infections?

6. What can prevent some viral infections?

7.Fill in the gaps using the given words.

long molecules / helical / eliminate / viral infections / protects / influenza / protein coat / measles / genetic / complex / prevent / surrounds / antiviral drugs

A virus consists of two or three parts: genes, a _____________ and an envelope of fat. DNA or RNA are _________ that carry the ___________ information. A protein coat ________ the genes. An envelope of fat __________ and protects viruses. Viruses may be __________ and icosahedral or have more _________ structures. __________________ cause diseases in human and animals. Common colds, ___________, chicken-pox and _____________ are caused by viruses. The immune system helps to ______________ viruses. ________________ treat viral infections. Vaccines can ____________ some viral infections.

Topic 42. Bacteria

Do you know that the term bacteria was introduced in the 19th century by the German botanist Ferdinand Cohn (1828-98)? Studying this topic you’ll be able to enrich your knowledge about bacteria, their shapes, habitant and influence on the living organisms.

1.Arrange (расположите) the sentences according to the given titles. Translate the sentences.

1. General characteristics

……………………………………………………………………………………….

2. Shapes of bacteria

……………………………………………………………………………………….

3. Habitat (среда обитания) of bacteria

………………………………………………………………………………………

4. Harmful bacteria

………………………………………………………………………………………

5. Beneficial bacteria

………………………………………………………………………………………

1. curved – изогнутый

2. comma-shaped – имеющий форму запятой

3. cluster of grapes – гроздь винограда

4. anthrax – сибирская язва

5. fertile – плодородный

6. inhibit – останавливать, подавлять

7. lactic acid – молочная кислота

1. Some types of bacteria can cause diseases and become harmful to the environment, animals and humans.

2. Bacteria in our digestive system help to convert milk protein into lactic acid and inhibit the growth of potentially harmful bacteria.

3. Bacteria is commonly found in the ground, water and in other living organisms.

4. Bacteria (bacterium) are a large group of minute single-celled microorganisms.

5. Bacteria help produce the food we eat and keeps the soil fertile, it also helps us digest our food.

6. Some rod-shaped bacteria, called vibrio (вибрион), are slightly curved or comma-shaped; others, can be spiral-shaped, called spirilla.

7. Some bacteria offer benefits that we likely could not live without.

8. Many bacteria exist as single cells, others form pairs, chains and group together in "cluster of grapes".

9. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a milliliter of fresh water.

10. Bacteria vary in shapes.

11. They cause infectious diseases, including cholera, syphilis, anthrax, leprosy and bubonic plague.

12. Most bacterial species are spherical (cocci), rod-shaped (bacilli).

13. Bacterial infections are treated with antibiotics.

14. They are among the oldest living organisms on the Earth.

Shapes of bacteria