gradient assisted by protein carrier molecules. B. movement of ions and molecules
along a concentration gradient. C. transport of molecules and ions against their
concentration gradient. D. water movement through a semi-permeable membrane
Answer is A: facilitated refers to the role of the protein carriers. The other choices refer
to diffusion, active transport and osmosis respectively
2) What do fi broblasts, chondroblasts, osteoblasts and haemocytoblasts have in
common? A. they are all types of white blood cell. B. they are all macrophages. C. they
are all immature cells. D. they are all types of epithelial cell.
Answer is C: the suffi x “-blast” implies that these cells have not yet fi nished their
differentiation. That is are immature.
3) The resting membrane potential of a cell is the consequence of which of the following
concentrations of ions? A. High K + and Cl − outside the cell and high Na + and large
anions inside the cell. B. High K + and Na + outside the cell and high Cl − and large
anions inside the cell. C. High Cl − and Na + outside the cell and high K + and large
cations inside the cell. D. High Ca 2+ and Na + outside the cell and high K + and large
cations inside the cell
Answer is C: These ionic species are largely responsible for the membrane potential
(cations are negative ions). While there is a higher concentration of Ca outside the cell
than inside, there are fewer Ca than Cl ions.
4) . Membrane proteins perform the following functions EXCEPT one. Which One? A. form
the glycocalyx B. act as receptor proteins C. form pores to allow the passage of small