The graph shows changes in global food production and global yields of food crops from 1980 to 2010.

(i) Referring to the graph, briefly describe the change in food production in India from 1980 to 2010.

(ii) Other than increasing global yield, state one reason why global production has increased.

Explain two ways in which the yield of some food crops can be increased.

Referring to two diseases, compare the factors affecting their spread from place to place

(i)

Award [1] for recognition of increase, [1] for recognition of step/steps and [1] for some correct quantification. For example: 250-300m tonnes in 1980 and 500-750m tonnes in 2010 (both years do not need to be quantified for the additional [1].

(ii)

Award [1] for recognizing that a greater area of land (new land) is now being cultivated/farmed. For example, “increased irrigation has led to more land being farmed”, or, “the use of HYVs/GMOs allows two or more crops per year from the same plot”.

Note: yield is not the same as output.

Reasons for increases in yield include: increased use of fertilizers; pesticides; irrigation; adoption of high-yielding varieties.

Accept other valid suggestions.

Award [1] for identification of valid factor, [1] for its development, and [1] for a clear link to yield rather than just output.

For example:
Yield may increase if more farmers apply more or better fertilizers [1] to their crops.
This provides plants with extra nutrients [1] and means that they produce more crops off the same area of land [1].
Yields (amount produced off a given area of land) [1] may increase if farmers use pesticides more effectively [1] because pests that normally reduce the yield of that crop are reduced or eliminated [1].

Geographic factors include environmental, physical, demographic, socio-economic, etc. The factors that are relevant will depend on the two
diseases chosen, and on any particular examples utilized in the response.

Good responses may draw comparisons using concepts such as diffusion, spread by relocation, the presence or absence of barriers to diffusion.

Responses at band D are likely to describe some factors that influence the spread of two diseases (do not expect balance).

At band E, expect either greater explanation of the factors affecting the spread of both diseases with located examples, or some explicit comparison focused on key factors/concepts.

At band F, expect both.

If only one disease is referred to, the response may not advance beyond band C.

Marks should be allocated according to the markbands.

(i) Some candidates had problems in interpretation of the graph, although most were able to recognize overall increase. There was some incorrect quantification and candidates frequently used figures for production rather than yield.

(ii) Very few gave a correct answer. Many gave the reason as increase in population, or use of HYVs (high yield varieties). The question referred to global production, rather than yields.

This was often poorly answered; candidates referred to output, rather than yield. Where correct factors were given, they were often not developed as to why yields increased.

Generally well answered. Good responses discussed types of diffusion and barriers, and gave located examples. Some focused on factors causing the diseases, rather than why they spread from place to place. Those that selected a lifestyle disease, such as obesity, were sometimes self-limiting in scope.