Maize originated from the wild plant teosinte, which is native from Mexico down to Argentina. It is believed that domesticated maize came from teosinte just one time. Maize remains have been discovered at archaeological sites that are 5500 years old.
(a(i))[2]
Compare the genetic diversity found in teosinte with that in cultivated maize.
(a(ii))[3]
Suggest causes for the differences in genetic diversity between teosinte and cultivated maize.
(a(iii))[2]
Explain how this data supports the idea that wild relatives of crop plants, such as maize, ought to be conserved.
(b)[3]
Many farmers now grow maize from seeds produced by crossing two different homozygous parents. Explain why this is done.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Higher in teosinte than in maize” …