IB Biology SL 2.3.3 Stem-Cell Release Evidence Question Bank
Practise IB Biology SL 2.3.3 using the exact SL evidence on drug-response controls, stem-cell release and CXCL12 mRNA production.
- Syllabus
- First assessment 2025
- Course
- Biology SL
- Level
- SL
Practise IB Biology SL 2.3.3 using the exact SL evidence on drug-response controls, stem-cell release and CXCL12 mRNA production.
Stem cells in the bone marrow can be forced into blood vessels in a process called mobilization. Mobilization of stem cells from the bone marrow into the blood vessels represents the basis for modern bone marrow transplantation procedures.
To test the effect of light on the mobilization of stem cells, mice were subjected to a simulated "jet lag" by advancing the light-dark cycle by 12 hours. This was done by subjecting mice to a 24 -hour light period before the results shown in the graph were recorded. The results were compared to the stem cells in control mice under normal conditions of 12 hours of light ( □ ) and 12 hours of darkness ( dark box) and 12 hours of darkness ( dark box ).


Compare the effect of isoprenaline and clenbuterol with the normal release of stem cells and the production of mRNA for CXCL12.

clenbuterol and isoprenaline both produce more stem cells than control; clenbuterol releases fewer stem cells than isoprenaline / isoprenaline releases the most stem cells; isoprenaline produces the least mRNA for CXCL12; clenbuterol produces the same amount of mRNA for CXCL12 as control;