Passage - 1 It is hard to predict how changes in the climate and the atmosphere's chemistry will affect the…
Passage - 1
It is hard to predict how changes in the climate and the atmosphere's chemistry will affect the prevalence and virulence of agricultural diseases. But there is a risk that such changes will make some plant infections more common in all climatic zones, perhaps catastrophically so. Part of the problem is that centuries of selective breeding have refined the genomes of most high-value crops. They are spectacular at growing in today's conditions but genetic variations that are not immediately useful to them have been bred out. This is good for yields but bad for coping with changes. A minor disease or even an unknown one could suddenly rampage through a genetically honed crop.
With reference to the above passage, the following assumptions have been made:
I. Global climate change can result in the migration of several plant diseases to new areas.
II. Scientific understanding of the wild relatives of our present crops would enable us to strengthen food security.
Which of the above assumptions is/are valid?
I only
II only
Both I and II
Neither I nor II
Solution
Assumption I is valid - the passage's warning that climate changes will make plant infections 'more common in all climatic zones' presupposes that diseases can spread to new areas. Assumption II is valid - the passage's concern that useful genetic variations have been 'bred out' implies that understanding wild relatives (which retain those variations) would help strengthen food security. Both are valid.