Biology Paper 21
May / June 2016·5090·9 questions
Mock exam: 75 min, official timing
Question paper
Question 1
Question 2
Question 3
Question 4
Question 5
Question 6
Question 7
Question 8
Question 9
Mark scheme
Question 1
1(a)(i)[1]
1(a)(ii)[2]
1(a)(iii)[1]
1(b)[3]
Question 2
2(a)[2]
2(b)[6]
2(c)[4]
Question 3
3(a)[6]
3(b)[4]
Question 4
4(a)(i)[3]
in nucleus (human) / within nuclear membrane ORA ;
in cytoplasm (bacteria) ;
thread + plasmid(s) (bacteria) ;
correct reference to chromosomes AW ;
genes / chromosomes paired (human) ; [max 3]
4(a)(ii)[2]
(cell) wall ; (cell) membrane ; [2]
4(a)(iii)[3]
4(a)(iv)[1]
4(a)(v)[1]
fermenter ;
A bioreactor [1]
Expected Answer Additional Guidance Mark
4(b)[4]
Question 5
5(a)[1]
5(b)(i)[2]
5(b)(ii)[4]
(resistant) reproduce ;
reference to (resistant) allele / gene ;
inherited / passed on ;
reference to repetition over many generations ; (resistant) become more common ;
reference to evolution ;
A ORA for each marking point [max 4]
[Total: 7] Expected Answer Additional Guidance Mark
Question 6
6(a)(i)[1]
stomach ; [1]
6(a)(ii)[6]
enzyme and substrate are lock and key ;
reference to optimum pH / (hydrochloric) acid (in stomach) ;
active site ;
complementary AW ;
substrate ;
if pH changes / alkaline ;
enzyme denatured / changes shape AW ; (substrate) no longer fits ; [max 6]
6(b)[3]
Question 7
7(a)[5]
7(b)[5]
Question 8
8(a)[2]
8(b)[8]
Question 9
9(a)[3]
9(b)(i)[5]
9(b)(ii)[2]