page 04 5. The table shows three examples of gene transfer. Plasmid transfer by bacteria Sexual reproduction by mice Asexual reproduction by bacteria 1 3 2 Which of these examples illustrate horizontal gene transfer? A 2 only B 3 only C 1 and 2 only D 1 and 3 only 6. Sickle cell anaemia is a human condition that affects haemoglobin, reducing the blood’s ability to carry oxygen. It is caused by a mutation that changes one adenine base to thymine. This results in one amino acid in haemoglobin being changed. The mutation that causes sickle cell anaemia is A deletion B insertion C substitution D translocation.