Arizona State University (ASU) Biology of Plants Exam 1 Practice

Absorption of water and minerals from soil happens mainly through the roots. Root hairs dramatically increase the surface area for uptake, allowing minerals to be taken into root cells by active transport, while water enters by osmosis due to water potential gradients. Once inside, these substances move into the xylem and are transported upward to the rest of the plant. Leaves and stems don’t primarily collect nutrients from soil—they mainly use water and minerals that have already been taken up and transport them, while leaves handle photosynthesis and gas exchange. Flowers are reproductive structures and not involved in soil uptake. So, the organ responsible for collecting minerals and water from the soil is the roots.