[Campbell Biology P.836] How do plant roots respond to varying concentrations of nitrate ava... | Practice Question

How do plant roots respond to varying concentrations of nitrate availability in the soil?

  • A: They branch extensively in areas with low nitrate availability and grow straight through nitrate-rich pockets.
  • B: They show no significant change in branching pattern regardless of nitrate concentration.
  • C: They grow straight through pockets of low nitrate availability but branch extensively when encountering a pocket rich in nitrate.
  • D: They only branch when nitrate levels are consistently high across the entire soil profile.

Explanation

Plants rapidly adjust the architecture and physiology of their roots to exploit patches of available nutrients. When roots encounter pockets of low nitrate availability, they extend straight through them instead of branching. Conversely, when encountering a pocket rich in nitrate, a root will branch extensively there and its cells will synthesize more proteins involved in nitrate transport and assimilation, absorbing nitrate more efficiently.