UVIC BIO 150 final exam Correct Questions & Answers(GRADED A+)

what acquires nutrients from air water and soil - ANSWER plants what is 96% of plants' dry weight? - ANSWER - organic carbon-containing compounds how does a plant get carbon? - ANSWER carbon comes from CO2 absorbed by plant leaves & integrated into organic compounds (e.g., glucose) by photosynthesis what do plants get from soil? - ANSWER - water - minerals - some O2 what part of roots controls solute uptake? - ANSWER The plasma membranes what must solutes move through to reach the water conducting xylem tissue at the center of the root - ANSWER must move through root epidermis & cortex - this process involves passage across plasma membranes of root cells plasma membranes are - ANSWER selectively permeable, allowing entry of needed minerals and keeping out unneeded or toxic substances two possible routes to a plants xylem - ANSWER 1) intracellular 2) Extracellular intracellular route to xylem is when... - ANSWER water & solutes cross plasma membrane of root hair, travel through passages (plasmodesmata) between cells to xylem the extacellular route to xylem is when... - ANSWER solution moves within cell walls and extracellular spaces; does not cross any plasma membranes until it hits the Casparian strip What is the Casparian Strip and what does it do - ANSWER - a continuous waxy barrier that stops water and solutes from entering the xylem through cell walls - forces water & solutes to cross a plasma membrane into an endodermal cell (the ring of cells around a vascular bundle) - this plasma membrane regulates mineral uptake for the the intercellular route.