IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Metabolism-Diffusion
Topic :Metabolism– Weightage : 21 %
All Questions for Topic : Nutrition,Digestion,Biochemistry and enzymes,Movement and transport,Diffusion,Osmosis,Gas exchange,Circulation,Transpiration and Translocation,Homeostasis
Experiment
A model cell only needs to have a membrane and cytoplasm for osmosis to occur. The membrane can be made out of the PVC film that is used to seal food items (known as plastic wrap or cling
film). It is about 10 μm thick, whereas a cell membrane is 10 nm thick.
Question:
What is the size ratio between the thickness of a cell membrane and that of the plastic film?
▶️Answer/Explanation
Ans: 10 micrometres/μm to 10 nanometres/nm; 10 micrometres = 10,000 nanometres; ratio is 1,000 to 1.
Question:
What is the advantage of making the size ratio for the diameter and the membrane thickness the same?
▶️Answer/Explanation
Ans: Scale model; more realistic; more likely to behave like the thing being modelled.