Biology 1202 Exam 5 Questions and Answers| New Update with 100% Correct Answers
Chapter 36 -- Resource Acquisition and Transport in Vascular Plants
"materials" required for life nutrients
nutrition in all organisms involves 4 main steps : - acquisition of nutrients
- digestion, if required
- distribution of nutrients throughout the body
- synthesis of molecules for the organism's body
starting material : plants elements and small molecules
starting material : animals large organic molecules
digestion : plants usually none
digestion : animals required to break large molecules down to building blocks
distribution : plants driven by osmosis and evaporation
distribution : animals pumping mechanism for most
synthesis of molecules : plants can do it all
synthesis of molecules : animals must acquire through some diet
,plants acquire all their nutrients from : - soil (minerals)
- water
- air
transport in vascular pants occurs on three scales : 1. transport of water and solutes by
individual cells
2. short-distance transport of substances from cell to cell at the level of tissues and organs
3. long-distance transport (bulk flow) with xylem and phloem
transport of water and solutes by individual cells occurs via transmembrane route
the diffusion of free water across a membrane osmosis
water potential (Ψ) the physical property that predicts the direction in which water will flow
Water potential (Ψ) is affected by - Solute potential (ΨS)
- Pressure potential (ΨP)
solute potential (ΨS) determined by concentration of dissolved molecules
pressure potential (ΨP) determined by the physical pressure on a solution
water potential equation Ψ = Ψs + Ψp
water moves in the direction where the water potential is lower
, symplastic route allows for the short-distance transport of substances from cell to cell at the
level of tissues and organs
symplastic route also used for long-distance transport (bulk flow) within xylem and phloem
apoplastic route allows movement of material (water and solute) around the outside of cells
and can occur over long distances as long as no barrier to the route exists
4 step process of mineral absorption by roots 1. active transport into root hairs
2. diffusion through root hair cytoplasm to endodermis cells vi their apoplastic or symplastic
route
3. active transport from endodermis cytoplasm into cell or the extracellular space of the
vascular cylinder
4. diffusion into the xylem
Casparian strip "leakproofs" the vascular cylinder, retaining the concentrated mineral
solution within the extracellular space of the vascular cylinder
water moves straight in from outside of root hairs into xylem by osmosis
bulk flow water and dissolved minerals move from roots to stems and leaves
- water and minerals move together
cohesion-tension theory 1. cohesion
2. tension
cohesion (cohesion-tension theory) water within xylem tubes sticks together
- water molecules in the xylem tube resist being pulled apart
Chapter 36 -- Resource Acquisition and Transport in Vascular Plants
"materials" required for life nutrients
nutrition in all organisms involves 4 main steps : - acquisition of nutrients
- digestion, if required
- distribution of nutrients throughout the body
- synthesis of molecules for the organism's body
starting material : plants elements and small molecules
starting material : animals large organic molecules
digestion : plants usually none
digestion : animals required to break large molecules down to building blocks
distribution : plants driven by osmosis and evaporation
distribution : animals pumping mechanism for most
synthesis of molecules : plants can do it all
synthesis of molecules : animals must acquire through some diet
,plants acquire all their nutrients from : - soil (minerals)
- water
- air
transport in vascular pants occurs on three scales : 1. transport of water and solutes by
individual cells
2. short-distance transport of substances from cell to cell at the level of tissues and organs
3. long-distance transport (bulk flow) with xylem and phloem
transport of water and solutes by individual cells occurs via transmembrane route
the diffusion of free water across a membrane osmosis
water potential (Ψ) the physical property that predicts the direction in which water will flow
Water potential (Ψ) is affected by - Solute potential (ΨS)
- Pressure potential (ΨP)
solute potential (ΨS) determined by concentration of dissolved molecules
pressure potential (ΨP) determined by the physical pressure on a solution
water potential equation Ψ = Ψs + Ψp
water moves in the direction where the water potential is lower
, symplastic route allows for the short-distance transport of substances from cell to cell at the
level of tissues and organs
symplastic route also used for long-distance transport (bulk flow) within xylem and phloem
apoplastic route allows movement of material (water and solute) around the outside of cells
and can occur over long distances as long as no barrier to the route exists
4 step process of mineral absorption by roots 1. active transport into root hairs
2. diffusion through root hair cytoplasm to endodermis cells vi their apoplastic or symplastic
route
3. active transport from endodermis cytoplasm into cell or the extracellular space of the
vascular cylinder
4. diffusion into the xylem
Casparian strip "leakproofs" the vascular cylinder, retaining the concentrated mineral
solution within the extracellular space of the vascular cylinder
water moves straight in from outside of root hairs into xylem by osmosis
bulk flow water and dissolved minerals move from roots to stems and leaves
- water and minerals move together
cohesion-tension theory 1. cohesion
2. tension
cohesion (cohesion-tension theory) water within xylem tubes sticks together
- water molecules in the xylem tube resist being pulled apart
