You can see how old people are
The uncertainty principle<span>, also known as </span>Heisenberg's uncertainty principle<span>, is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables</span>
In comparison they both show feeding relationship in an ecosystem.
In contrast, a food chain is a simple linear feeding relationship while a food web is a complex feeding relationship.
2) The arrows is to show the direction of the feeding relationship
In plants the reproductive structure that produces pollen and seeds is the xylem is the answer
