News by Levels · Level 2 · For teachers
Teacher guide & answers
In this lesson: Explain the proposed mechanism and the limits of the comparison.
Mouse Study Tests Heart Muscle Repair
How to use these two pages
Give learners the student worksheet. It contains the story and questions, without the answers. Keep this guide for yourself. Use it to lead the activity and explain the answers afterwards.
Student worksheetA simple 15–20-minute lesson
- Before reading · 2 minutes
Show the title. Ask: “What do you think this story is about?”
- Read and answer · 8–10 minutes
Give out the student worksheet. Learners read for the main idea, then reread to answer the 2 questions. They can compare answers with a partner.
- Discuss and write · 5–8 minutes
Check the answers below together. Ask learners to point to the clue in the story, then finish with the open question.
Adjust the support: Let learners use word help or Level 1 if needed. For a challenge, compare the wording in another level. This activity is not a proficiency test.
Answers to the 2 questions
The question numbers match the student worksheet. Each answer includes a reason and the clue learners can find in the story.
What was the effect of activating the proteins?
Correct answer: A — Heart cells were encouraged to divide
Why: The opening paragraph connects protein activation with cell division.
Clue in the story: An experimental mRNA treatment temporarily activated two proteins in mouse heart cells, encouraging them to divide. Cambridge reported the study on November 9.
Which comparison does the reported result support?
Correct answer: C — Treated mice versus comparison mice
Why: The second paragraph describes a comparison between mice.
Clue in the story: After heart attacks, treated mice pumped about 10% more blood per beat than comparison mice. The result does not establish safety or effectiveness in humans.
The open question: accept different answers
Ask learners: Explain how the treatment worked and what remains uncertain.
One possible answer: The mRNA temporarily activated two proteins, encouraging mouse heart cells to divide. The blood-pumping result was better than in comparison mice, but human safety and effectiveness remain unestablished.
This is an example, not the only correct answer. Look for a relevant idea, a reason and the learner’s own words. Learners can answer aloud or write one or two sentences.
Grammar to discuss
A temporary action
temporarily activated
Temporarily limits the duration of activation; it does not describe a permanent genetic change.