Describe how a bacterial cell differs from a typical animal cell.

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2015). The mark or mark type is shown in brackets.

1. [max 3] bacterial cell has cell wall; no (true) nucleus ; ref. different arrangement of DNA eg plasmid ; (may) have flagella; capable of independent existence ; size reference e.g. bacterial cells smaller ; bacteria produce spores ; bacteria have slime capsules/no mitochondria/smaller ribosomes ;
2. [max 3] conversion of nitrogen; to ammonium/amino acids ; free-living (bacteria) or named (Azotobacter) ; in root nodules/named bacteria (Rhizobium) ; leguminous plant / named plant;
3. [max 4] decomposition/breakdown/decay; of organic matter/faeces/urea; using up O2/aerobic/dissolved oxygen decreases ; for respiration; resulting in lack of O2/anaerobic conditions ; ref. eutrophication;