According to last year's grade boundaries, it was 57% between both papers for an A overall, so not that bad
Yes, I did mention parts about natural selection. What I did, was I compared the allele frequencies of those who are heterozygous, homozygous for condition, and homozygous without allele.
Heterozygous - Resistant to cerebral malaria and won't develop sickle cell anaemia. This will lead to an increase in heterozygous individuals, so frequency of allele will increase. More likely to survive and reproduce as they can survive against the selection pressure and pass on the sickle cell allele.
Homozygous - Likely to develop severe sickle cell anaemia, so frequency of the allele may decrease
Homozygous without allele - Will not develop sickle cell, but vulnerable to the malaria, which is endemic in the region. This may lead to a decrease of non-sickle cell alleles.
I have no idea if it's right haha.
Also, I think you will lose marks on the 6 marker where you mentioned concentration. You are likely to lose other marking points since your investigation doesn't actually answer the question.
Overall, I found it okay. I think i did get the Hardy Weinberg equation wrong. I got 192, how about you?