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Bio Ch 36
Transport in Vascular Plants
Question | Answer |
---|---|
Which of the following would least likely to affect osmosis in plants? | receptor proteins in the membrane |
Active transport involves all of the following except the | slow movement through the lipid bilayer of a membrane |
Like many plants process, transport of various material in plans at the cellular level requires all of the following except: | xylem membranes |
Which of the following is an example of osmosis? | flow of water out of a cell, flow of water between cells |
The amount and direction of movement of water in plants can always be predicted by measuring which of the following? | water potential |
Which of the following is true concerning the water potential of a plant cell? | It is equal to zero when the cell is in pure water and is turgid. |
Your laboratory partner has an open beaker of pure water. By definition, the water potential of this water is? | zero |
Which of the following has an effect on water potential in plants? | air pressure, water-attracting matrices and dissolved solutes |
If Wp =.3 MPa and Ws = -.45 then this equals | -.15 MPa |
The value for water potential in a root was found to be -.15 MPa. If you take the tissue and place it in a solution of sucrose with a -.23, water will flow where? | from the tissue into the sucrose |
COmpared to a cell with a few aquarporins in its membrane, a cell containing many aquaporins will... | have a faster rate of osmosis |
Some botanists agree tha the entire plant should be considered a single unit rather than a composite of may individual cells. Which of the following cellular structures cannot be used to support this view? | tonoplast |
Which of the following statements is false about bulk flow? | It depends on the force of gravity on a column of water. |
Which of the following statements about xylem is incorrect? | It transports mainly sugars and amino acids |
Which of the following would likely not contribute to the surface area available for water absorption from the soil by a plant root system? | endodermis (they are water resistant and waxy) |
Root hairs are most important to a plant because they ... | increase the surface area for absorption |
What is the role of proton pumps in root hair cells? | acquire minerals form the soil |
In plant roots, the casparian e strip is correctly described by which of the following? | It ensures that all water and dissolved substance must pass through a cell before entering the stele |
All of the following describe an important component of the long-distance transport process in plants except | endodermis Casparian strip |
Pine seedlings grow in sterile potting soil grow much slower than seedlings grown in soil from the are where the seeds were collected. This is most likely because: | the normal symbiotic fungi are not present in the sterilized soil and water and mineral uptake is faster when mycorrhizae are present. |
A water molecule could move all the way through a plant from soil to root to leaf to air and pass through a living cell only once. this living cell would be part of what structure? | the endodermis |
The following factos may sometimes play a role int he movement of sap through the xylem. Which one depends on the direct expenditure of ATP by the plant? | concentration of ions in the symplast |
What is the main cause of guttation in plants | root pressure |
One is the most likely to see guttation in small plants when the.. | root pressure exceeds transpiration pull |
What is the main force by which most of the water within xylem vessels moves toward the top of a tree? | evaporation of water through the stoma |
In which plant cell or tissue would the pressure component of water potential most often be negative? | stem xylem |
Water potential is generally most negative in which of the following part of a plant? | mesophyll cells of the leaf |
Which of the following has the lowest (most negative) water potential? | leaf air spaces |
Which of the following is responsible for the cohesion of water molecules | hydrogen bonds between the oxygen atom of one water molecule and a hydrogen atom of another water molecule |
Active transport would be least important in the normal functioning of which of the following plant tissue types? | stem xylem |
Guard cells do which of the following? | help balance the photosynthesis-transpiration compromise |
All of the following normally enter the plant through the roots except: | carbon dioxide |
Photosynthesis begins to decline when leaves wilt because | stomata close, preventing CO2 entry into the leaf |
The water lost during transpiration is an unfortunate side effect of the plant's exchange of gases. However, the plant derive some benefit from this water loss in the form of.. | evaporative cooling and increased turgor |
Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of a tree? | warm, dry day |
If the guard cells and surrounding cells in a plant are deficient in potassium ions, all of the following would occur except.. | leaf temperatures would decrease |
The opening of stomata is thought to involve... | an increase in the osmotic concentration of the guard cells |
Which of the following experimental procedures would most likely reduce transpiration while allowing the normal growth of a plant? | Increasing the level of carbon dioxide around the plant. |
All of the following are adaptation that help reduce water loss from a plant except.. | transpiration |
Phloem transport of sucrose can be describe as going from "source to sink". Which of the following would not normally function as a sink? | mature leaf |
Which of the following is a correct statement about sugar movement in phloem? | Movement can occur both upward and down in the plant. |
Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about transport? Phloem transport --- from the --- source to the--- sink. | Phloem transports sugars from the leaf source to the apical meristem sink. |
Explain the mass flow of materials in the phloem? | leaf cells produce sugar by photosynthesis; Sugar is transported from cell to cell in the leaf; Solutes are actively transported into sieve tubes; water diffuses into the sieve tubes; sugars moves down the stem |
Water flows into the source end of a sieve tube because | sucrose has been actively transported into the sieve tube, making it hypertonic |
Which one of the following statements about transport of nutrients in phloem is false? | Companion cells control the rate and direction of movement of phloem sap. |
According to the pressure flow hypothesis of phloem transport, | solute move from a high concentration in the "source" to a lower concentration in the "sink" |
Which of these involves a symbiotic relationship? | mycorrhizae |
------ increase the surface area of roots. | Root hairs and mycorrhizae |
In roots the ------- forces water and solutes through the plasma membranes of the ----- cells before entering the -------. | Casparian strip; endodermis; xylem |
Sugars move from leaves into the ------ of ----- by ------. | Sugars move from leaves into the sieve-tube members of the phloem by active transport. |
The water pressure that pulse water and sugar from sugar source to sugar sink is referred to as ----. | bulk flow |
Transpiration in plants requires all of the following except | active transport through xylem cells. |
Which of the following is an advantage of tracheids over vessels for long-distance transport to great heights? | Adhesive forces are proportionally greater in narrower cylinders than in wider cylinders and Cohesive forces are greater in narrow tubes than in wide tubes of the same height. |
Guard cells are the only cells in the epidermis that contain chloroplasts and can undergo photosynthesis. This is important because... | ATP is required to power proton pumps in the guard cell membranes. |