They are all part of the biological of community
The fibrous outer layer of the eye which retains the overall shape of the eye is the sclera
<span>The taproot is modified to be able to be used for food storage. It can store both sugars and starches, both of which are food for the plant. The leaf is used for uptake of both sucrose and glucose, which are food for the plant. So both of these structures aid in feeding the plant.</span>
My best guess is the third option, that pathogens with previous exposure are quickly recognized and killed.