The cell. Кулагина Ж.Д. - 10 стр.

                                        10


      Ex. 10. Convert the following statements into Direct speech.

Model: 1) They told me to go home.
          They said to me: "Go home."
      2) They told me not to go home.
          They said to me: "Don't go home".

1. The teacher asked us to observe some general Lab Safety Rules. 2. He asked
us to tie back long hair when we work with an open flame in the laboratory. 3.
The teacher told us not to mix chemicals or perform unscheduled experiments
without his approval. 4. The teacher told us to never use chemicals from an
unlabeled container. 5. He asked us not to taste, smell or touch chemicals unless
specially instructed. 6. The teacher ordered his students to wear safety gaggles
during experiments involving dissection, heating, hammering or while using
acids, bases and other chemicals. 7. He told us to stay away from students who
were experimenting if we didn't have gaggles on. 8. He asked us to be careful
picking up hot materials, especially glass ware. 9. He prohibited us to return
excess chemicals back to their container.

                                      Step 2
      Ex. 11. Read text А.

                                    TEXT A
       А tiny amount of protoplasm is called a cell. A typical cell is spherical in
form and contains at least three parts: the nucleus, the cytoplasm and the cell
wall.
       The nucleus.
       The protoplasm of a cell is not homogeneous but contains within it a
number of specialised structures. The nucleus is chief among them. This is an
approximately spherical body, denser than the rest of the protoplasm and
bounded by a definite membrane. The nucleus is evidently the directing centre
for the more important physiological activities of the cell, such as the synthesis,
digestion and assimilation of foods, the formation of the cell wall, cell division,
growth and transmission of hereditary traits in reproduction. Cells from which
the nucleus has been removed artificially will often live for a time but fail to
carry on actively their normal metabolic processes.
       Chemically, the nucleus is much like the rest of the protoplasm, except the
fact that it contains a large amount of a characteristic protein, called nuclein of
which phosphorus is an important element.
       A cell usually contains a single nucleus, but in certain cells there may be
many nuclei. Among some of the algae and fungi, for example, the entire plant
body is a single huge cell with hundreds of nuclei. Such forms demonstrate that