L2
讲座
1. What does the professor mainly discuss?
Reasons that biofilms were poorly understood until the 1970s
The formation and behavior of a type of bacterial community
Potential benefits associated with bacterial growth
The size and chemical composition of biofilms
2. The professor describes the development of a bacterial biofilm. Summarize the development by putting the steps in the correct order. A. The bacteria send signals to one another.
The bacteria attach to a surface.
The bacteria reproduce and form a colony.
The bacteria are free-floating.
The bacteria produce a sugary substance
3. What does the professor say about the water channels in biofilms?（多选题）
They allow bacteria to change locations within the biofilm.
They interfere with the growth of the biofilm.
They serve to bring in food and dispose of waste.
They are not created by all species of bacteria.
4. According to the professor, how are biofilm bacteria different from free-floating bacteria?
Biofilm bacteria have a lower reproduction rate
Biofilm bacteria need more nutrients to produce polysaccharide.
Biofilm bacteria are less vulnerable to disinfectants.
Biofilm bacteria cannot separate from other bacteria.
5. What point does the professor make when she mentions the increase in biofilm research?
The results of prior research have been controversial
Prior research has focused on the benefits of biofilms.
Biofilms are difficult to remove.
Biofilms have become a major contributor to pollution.
6. Why does the professor say this:
To clarify her use of a term
To encourage the students to express their own opinions
To indicate that she is unsure about the date
To emphasize that advances in biological research take a long time
