Plant structure allows water and minerals to move up from the roots to the leaves and nutrients to move from the leaves down into the plant. Roots contain root hairs and mycorrhizae (fungus) to better absorb water via osmosis. Water then moves via the symplast or protoplast pathway to the endoderm. Thy xylem structure includes tracheids and vessel elements to move up the plant via bulk flow, the result of a pressure gradient caused by transpiration. As water evaporates from the leaves, it pulls the water behind it up through the xylem due to cohesion and adhesion. Nutrients travel through phloem, sieve-tube elements and their companion cells. Phloem sap moves from a sugar source to a sugar sink (like bulbs, fruit or young leaves) through translocation.
Water is absorbed by the roots
of plants and then distributed to the rest of the plant.
Root hairs and mycorrhizae
increase the surface area available for water absorption.
Water potential is influenced
by solute concentration and pressure. Water moves from areas of
higher water potential to areas of lower water potential.
Water and minerals enter the
root and travel to the vascular cylinders. Two routes for lateral
movement of materials through the root are the symplast and apoplast
endodermal cells surrounding the vascular cylinder are tightly
packed together and regulate the entry of water and minerals into
the vascular cylinder.
Transport of water and solutes
through the xylem relies on bulk flow. Bulk flow is the result of a
pressure gradient created by the loss of water from leaves through
transpiration. The cohesive and adhesive properties of water allow
bulk flow to occur by capillary action.
Phloem sap moves from a sugar
source to a sugar sink during translocation. A sugar source is a
site of sugar production. A sugar sink is a site of either the
consumption or storage of sugar.
Transport of Nutrients and Water in Plants
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
The book and CD package include two full length practice exams that are presented with all questions answered and explained. The author also presents detailed reviews of all test topics and includes multiple-choice and free-response questions with answers at the end of each topic's chapter.
This book includes a review of the AP Biology exam format and scoring, proven strategies for answering multiple-choice questions, and hints for tackling the essay questions. The practice tests include answers and explanations and there is also proven test-taking strategies for both the multiple choice and essay parts.