L3：
讲座
1. What is the lecture mainly about
The costs of extracting proteins from plants to make vaccines
The modification of seeds to increase plant reproduction
The benefits of using plant seeds to obtain proteins for vaccines
The use of proteins in animal cells to produce vaccines
2. According to the professor, what did the researchers learn about proteins produced from plant seeds
They produce antibodies that are effective in humans
They are difficult to extract.
They are more suitable for medicinal use than antibodies produced from bacteria and yeasts.
They do not survive as long as proteins produced from leaves
3. According to the professor, what is an advantage of using plant seeds rather than plant leaves to extract proteins
Proteins can be extracted more quickly from seeds than from leaves.
Proteins from seeds are more effective as medication.
Seeds can be stored without the proteins’ losing their effectiveness.
A single seed provides more protein than a single leaf.
4. Why does the professor mention insulin
To give an example of a protein that is used as medicine
To point out the most common protein produced from plant seeds
To give an example of a medication that can be stored for a long period
To explain why it is difficult to extract proteins from plants
5. Why does the professor discuss refrigeration
To emphasize the expense of producing proteins from plant seeds
To point out the cost-effectiveness of transporting seeds
To illustrate the difficulty of preserving some vaccines made from seed proteins
To emphasize the need for more high-tech laboratories for extracting plant proteins
6. Why does the professor say this:
To remind students of a lab experiment they recently completed
To encourage students to provide a summary of a previous lecture
To point out something that she thinks the students might not know
To use common knowledge to establish a starting point for the lecture
