K.C.S.E Biology Q & A - MODEL 2017PP1QN23

K.C.S.E Biology Q & A - MODEL 2017PP1QN23

The diagram below represents a set up during an experiment.

​(a) (i) What was, the experiment investigating? 
(ii) State the likely identity for substance K 
(iii) Explain your answer in (a) (ii) above 
(b) Account for the observations made in flask 2.

answers

​a.) i) To investigate how ants respond to moisture/water hydrotaxis (varied environments with/without moisture water); 
ii) Silica gel/anhydrous calcium chloride pellets/pyrogallic acid/dehydrating drying agent; 
iii) The colour of cobalt (II) chloride paper remained blue/all the moisture water vapour was absorbed/There was no water/moisture in the flask to change the colour of cobalt(II) chloride paper; 
b.) (More) ants were attracted) moved into the flask; due to the presence of moisture/water vapour; (evidenced by the change of cobalt (II) chloride paper to pink)