Question 5
HDoctors carried out a trial of a new stem cell treatment for a disease of the heart. 200 patients were given the new stem cell treatment. A different group of 200 patients were given the standard treatment. Figure shows the percentage of the patients in each group who were still alive in the five years after treatment.
Figure: The percentage of patients still alive in each of the five years after being given either the stem cell treatment or the standard treatment
a.[2]
Use Figure to compare the survival of the two groups of patients during the five years after treatment.
b.[2]
Calculate the number of patients given the standard treatment who were still alive 5 years after treatment.
c.[1]
The doctors concluded that the stem cell treatment is better than the standard treatment. Suggest one reason why more evidence is needed before this conclusion can be accepted.
1.2 Cell division Questions
63 exam-style questions on AQA GCSE Biology 1.2 Cell division, covering 1.2.1 Chromosomes, 1.2.2 Mitosis and the cell cycle, and 1.2.3 Stem cells. Each one has a worked solution and a mark scheme showing where the marks go.