Look at the chloride ion uptake. It is irrespective of the oxygen conc. whatsoever. Thus it is not move by active transport. Nitrate ions do howeverhttp://papers.xtremepapers.com/CIE/Cambridge International O Level/Biology (5090)/5090_s13_qp_12.pdf
Question 3?
And in question 4 why does the iodine test give black colour when we have BOILED amylase which means that the enzyme got denatured. Thus the enzyme wont act on it and the colour should be yellow.No?
4. Bioled amylase will mean no reducing sugars will be present (ie. starch will be there), and thus there is a postive test for starch