CIE iGCSE Co-Ordinated Science B9.4 Blood Exam Style Questions Paper 4
Question
(a) Red blood cells are specialised to transport oxygen.
Describe two ways that red blood cells are adapted for their function.
(b) A student investigates the effect of different concentrations of salt solution on red blood cells.
The student immerses the red blood cells in different concentrations of salt solution and observes the cells after immersion.
Table 10.1 shows the results.
(i) Identify the salt solution with the same water potential as red blood cells.
…………………………….. g/dm3
(ii) Explain the observation seen at 10.0g/dm3 in Table 10.1.
(c) The investigation is repeated with plant cells.
(i) Plants cells do not burst when immersed in 2.0g/dm3 salt solution.
Explain why.
(ii) State two uses of water in plant cells.
(iii) State the name of the type of plant cell specialised for absorption of water.
▶️Answer/Explanation
Ans :
10(a) any two from:
no nucleus ;
large surface area / biconcave (shape) ;
contains haemoglobin ;
10(b)(i) 8.0 (g per dm3) ;
10(b)(ii) water leaves the cell ;
by osmosis ;
the salt solution has a lower water potential (than the red blood cell) / water moves from an area of high water potential to
low water potential ;
10(c)(i) presence of cell wall ;
strengthens the cell ;
10(c)(ii) any two from:
solvent ;
photosynthesis ;
support / ref to turgidity / prevent wilting ;
transport of, minerals / mineral ions / ions ;
AVP ;
10(c)(iii) root hair (cell) ;