- Summary list for 9.1 Transport in xylem
- Mindmaps
- Exam style question about transport in xylem
- Model answer
- Exam style question about the properties of water.
- Model answer
- Model answer
- 9.1 Transport in xylem 1/1
Learn and test your biological vocabulary using these 9.1 Transport in xylem flashcards.
Summary list for 9.1 Transport in xylem
Leaf stomata & transpiration
- Leaves are adapted to absorb carbon dioxide from the air
- therefore transpiration can also occur in leaves and water is lost to the air.
Transport in xylem
- The structure of primary xylem vessels.
- Xylem vessels transport water from roots to leaves to replace water lost in transpiration.
- The cohesive and adhesive properties of water molecules allow water transport under tension in xylem and cell walls.
- The roots cells use active transport for the uptake of mineral ions (nitrates) which causes osmosis and the absorption of water.
- Xerophytic plants in deserts have adaptations for water conservation.
Adaptations of xerophytes
- Xerophytic plants in deserts have adaptations for water conservation.
Skills
- Ability to draw the structure of primary xylem vessels in stems from microscope slides.
- Recognition of structure and function of xylem. (essential idea)
- Use potometers to measure transpiration rates
- Design an experiment to test hypotheses about the effects of abiotic factors on transpiration rates.
Mindmaps
These diagram summaries cover the main sections of topic 9.1 Transport in xylem.
Study them and draw your own list or concept map, from memory if you can.
Try to turn the simple mindmap into the detailed mindmap from memory.
Exam style question about transport in xylem
Design an experiment to test hypotheses about the effects of abiotic factors on transpiration rates is an important skill from this topic.
Answer the question below on a piece of paper, then check your answer against the model answer below.
The rate of transpiration can be measured using a simple potometer, shown in the diagram. [3]
List three variables that should be controlled to ensure that only wind speed affected the movement of the bubble in the capillary tube. Explain their likely affect on the bubble movement. [3]
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Click the + icon to see a model answer.
Exam style question about the properties of water.
The link between the polarity of water, it's properties and the transpiration stream is an important concept.
Answer the question on paper and compare your answer to the model answer.
Describe how the properties of water aid the process of water movement in the xylem of a plant. (6 marks)
Examiner's hint: Describe questions require detail. Link a property of water to the process of transpiration.
Keep the answer to processes in the xylem, not transpiration.
Click the + icon to see a model answer.
Extra exam question on xylem structure and function Click to open.
Structure and function are closely linked in biological structures.
Answer the question on paper and compare your answer to the model answer.
Outline four ways in which the structure of xylem vessels is related to its function in transporting water from the roots to the leaves of a plant. (3 marks).
Examiner hint: Ensure that each sentence clearly links structure to function
This is a self marking quiz containing questions covering the topic outlined above.
Try the questions to check your understanding.
START QUIZ!
The image on the right shows a stained transverse section of cells in a dicot. leaf magnified about 400x.
Which of the labels in the diagram show the pallisade mesophyl of the leaf?
The labels are:
A: Pallisade mesophyll, B: Spongy mesophyll, C: Air space, D: Guard cell.
The image on the right shows a stained transverse section of cells in a dicot. leaf magnified about 400x.
Which of the labels in the diagram shows the cells which are best adapted to absorb CO2 from air in the air spaces of the lear?
Spongy mesophyll cells are surrounded by air, containing caarbon dioxide.
The image on the right shows a stained transverse section of cells in a dicot. leaf magnified about 400x.
Which of the following sequences best describes the path which oxygen takes within the leaf?
Oxygen is made during photosynthesis in the leaf, and it diffuses into air spaces and then out of the stomata.
The image on the right shows a stained, transverse section of cells in the vein of a dicot. leaf.
It is magnified about 400x.
Which of the labels shows Xylem vessels?
Xylem vessels have no cytoplasm and thick angular walls.
The red cells between A and B and after D are supportive cells surrounding the vascular bundle. Not xylem
Xylem cells are all sizes with thick cell walls, no cytoplasm and angular cell walls. they are found in the lower half of this vascular bundle towards the centre of the stem.
Many of the cells shown in this plant stem are xylem. It is magnified about x400.
Which of the following are adaptations of xylem vessels?
Mature xylem vessels have no cytoplasm. Together they form long tubes
They have thickening of the cell walls to prevent the collapse when water in them is under tention in the transpiration stream.
Which of the following statements explains the importance of adhesion to the transpiration stream?
Adhesion is an attraction between water molecules and the inner wall of xylem ducts and the cells of the leaf.
Then water column cannot be pulled away from the wall of xylem ducts due to strong adhesion of water. This helps to create tension, or transpiration pull.
Cohesion and adhesion are properties of water which are important to the transport of water in plants.
Which of the following statements discriminates best between cohesion and adhesion?
Cohesion is the phenomenon of attraction between similar molecules. The water molecules remain attracted by the cohesive force and cannot be easily separated from one another. This force maintains the continuity of the water column in xylem.
Drag and drop activities
Test your ability to construct biological explanations using the drag and drop questions below.
Active uptake of mineral ions in the roots causes absorption of water by osmosis.
Drag and drop the correct word or phrase into the gap to describe how plants absorb minerals from the soil.
sucrose active parasitic specific low ions hypertonic root surface osmosis fungi mutualistic concentration gradient protein ATP hypotonic
Plants absorb minerals from soil water against the by transport. This requires and several pumps in the root cell membrane, each pump being to a particular ion.
Some plants have a relationship with soil , Mycorrhiza. The fungus grows on the and actively absorbs that pass into the plant and passes from the plant tissue to the fungus.
Active absorption of minerals also creates root cell sap to soil water necessary for the inward of water from the soil into the root.
Explanation: Active transport proteins are specific to particular ions so several types are needed for the different ions required by the plant.
Halophyte (and xerophyte) adaptations to their environment is an important concept.
Drag and drop the correct term into the gap to describe halophyte adaptations to their environment.
loss removing Long osmosis saline surface area mesophytic stems gaining hydrophilic Sunken xerophytic Thickened humidity
Halophytes live in areas such as beaches, where the water is hence water gain by is lessened and the plants endure water stress.
This causes them to have habits to minimise water :
- Reduction of leaf .
- stomata to lessen water loss by maintaining high around the stomata.
- cuticle.
- Photosynthetic to compensate for reduced leaf size.
- , branching roots to reach for ground water.
They also may have structures for salt and are resistant to drought and damage..
Explanation and examiner hint: There are many similarities between halophytes and xerophytes as both have to endure water stress.
Everyone needs a bit of fun while they revise. Try this Transport in xylem terms card matching game
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