II. Put the verbs in brackets into the correct tense form
1. In the past few decades, many developments in physiology and embryology (result) from studies in cell biology, biophysics, and biochemistry.
2. A good science experiment simultaneously (not test) several variables.
3. In 1838 Mattias Schleiden (conclude) all plant tissues consisted of cells.
4. Probably the greatest biological problem of the future, (be) to find ways to curb environmental pollution without interfering with man's constant effort to improve the quality of his life.
5. The compound light microscope, shown in Figure 8, (use) two ground glass lenses to form the image.
6. The nurse (prepared) the instruments for the operation by the time the doctor came.
7. I hope next year she (enter) the Medical University.
8. The changes that (take) place since the origin of the cell are also thought to have occurred as a result of natural selection.
LISTENING COMPREHENSION
I. You will hear a text about cells’ movement. Before listening discuss the words and expressions in the box with your fellow students and teacher
glide
thrash
whip
fertilization
oar
to extrude
to anchor
flagellum (flagella)
cilium (cilia)
to propel oneself
to swallow
respiratory tract
inhaled dust
basal body
to search for food
dense, hairy appearance
a current of mucus
temporary pseudopodium
to pursue and devour prey
to roam the bloodstream
to stalk and engulf a bacterium or virus
II. Listen to the text and answer the questions below
1. Why do cells have to move?
2. What adaptation do they use for this purpose?
3. What is the difference between prokaryotic and eukaryotic flagella?
4. What eukaryotic cells use flagella as a means of motion?
5. Give an example of an organism that cilia for motion?
6. What functions do cilia perform in cells which do not move?
7. What are basal bodies?
8. Describe the principle of amoeboid motion?
9. Which types of motion in cells are faster and which are slower?
10. In what conditions is amoeboid motion most effective?