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Learn about the structure and function of a leaf, the transport systems of plants (xylem and phloem), and the process of transpiration. Identify the structures involved in plant transport and measure transpiration.
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Multicellular OrganismsKey Area 5Transport systems- Plants First Task… Collect your new learning Outcomes and stick them into your notebook
Multicellular OrganismsKey Area 5Transport systems- Plants Using the icing, create a toping for your cake associated with one of the key word related to KA 5
Plant transport systems Learning Intention: To learn the structure and function of the different parts of a leaf. To learn the structure and function of the xylem and phloem. To learn about transpiration in plants. Success Criteria: Identify the structures and their function in transport
Literacy, Numeracy, HWB: • I can make notes and organise them to develop my thinking, help retain and recall information, explore issues and create new texts, using my own words as appropriate. • LIT 3-15a / LIT 4-15a Skills for life, learning and work: • Understanding new scientific terms • Becoming confident in new biological terms • Apply knowledge when identifying structures under a microscope
Starter Activity Discuss with your partner: • What materials are transported around a plant? • How could they be transported?
Plant transport • Plant transport organs are: • roots • stems • leaves. • Label these in your • Jotter.
Leaves Upper Epidermis Waxy cuticle Palisade mesophyll Spongy mesophyll Lower Epidermis Guard Cell Guard Cell
Leaves • Why is the cuticle waxy? • Cuticle and Epidermis reduces water loss, by evaporation, from the surface of the leaf. • Water is needed in the leaves so the (palisade) mesophyll cells can photosynthesise. • The opening and closing of the stomata are controlled by the guard cells. They swell with water to open and empty of water to close. • The stomata allow CO2 to diffuse into the plant and O2 to diffuse out.
Leaf structure Leaf structure
Leaf structure Leaf structure
What else is transported throughout the plant? Plants contain two types of cell adapted for transportation. Xylem- transports water Phloemcells are living cells which transport sugars produced in the leaves up and down the stem to growing and storage tissues.
Xylem and phloem • The xylem and phloem are found in the vein of a plant. Vein containing xylem and phloem
Transpiration-Xylem • Once water has been absorbed into the plants it is carried by Xylem tissue towards the leaves for photosynthesis. (upwards) • Water and dissolved minerals (eg, Na, K) travel in Xylem. • It is dead tissue. • The Lignin rings help keep the Xylem tissue open.
Phloem • Phloem tissue is not directly linked to the transpiration stream. • They are situated next to Xylem tissue within a plant. • Unlike Xylem, Phloem tissue is alive and carries sugars and organic molecules all around the plant. (upwards and downwards) • Twig - Plant Transport : Twig
In your pairs, discuss and write down at least three differences between the structure of phloem and xylem. • Xylem is dead, phloem is alive. • Xylem has a thick lignin lining on it’s walls, phloem does not. • Xylem cells have no cell contents, phloem cells do. • Phloem has sieve plates, xylem does not
Transpiration The transpiration stream pulls water from the roots up to the leaves just like this. Xylem and phloem vessels in the stem
Transpiration Transpiration
Transpiration • Transpiration is the evaporation of water into the atmosphere from leaves of plants. • Water moves from the roots of a plant to the leaves. • Water is vital for the transport of minerals within a plant and for photosynthesis. • Water is lost through pores, called Stomata, that are on the underside of a leaf. • Twig - Transpiration
Transpiration-Roots • Root Hairs increase the surface area for the absorption of water from the surrounding soil. • Water moves into the root hair cells by osmosis. • Water then moves up the stem and into the leaves through the xylem. • Water exits through the stomata in the leaves. J A
Microscopes • Using Plant structure 1 slides- • Slide numbers 1, 2, 3, 5, 7, 8, 12 show structures in plants that involved in transpiration. • Root hairs, Xylem and Phloem can all be seen. • Task- Draw your field of view for at least 4 of the different slides.
Exit task • What is transpiration? • List 2 differences in the structure and function of the xylem and phloem. • How does water enter a plant? • What cells open and close the stomata in the leaf?
Plant transport systems Learning Intention: To learn the structure and function of the different parts of a leaf. To learn the structure and function of the xylem and phloem. To learn about transpiration in plants. Success Criteria: Identify the structures and their function in transport
Measuring transpiration Learning Intentions: To learn the structures and functions involved in the transpiration process. Success Criteria: Identify the structures and their function in transpiration. Identify how transpiration rate can be measured.
Literacy, Numeracy, HWB: • When I engage with others I can make a relevant contribution, ensure that everyone has an opportunity to contribute and encourage them to take account of others’ points of view or alternative solutions. • LIT 4-02a • I make full use of and value the opportunities I am given to improve and manage my learning and, in turn, I can help to encourage learning and confidence in others. • HWB 3-11a / HWB 4-11a Skills for life, learning and work: • Evaluate data in experiments • Becoming confident in new biological terms • Apply knowledge to experimental concepts • Inquiry and investigative skills
Starter Answer A
A Bubble Potometer leafy cutting Reservoir (zeroing mechanism) Airtight seal bubble water scale Measuring Transpiration
A Bubble Potometer leafy cutting Reservoir (zeroing mechanism) Airtight seal bubble water scale • A bubble is introduced to the capillary tube. • As water is taken up by the plant and lost from the leaves the bubble moves along the scale. • By comparing the start and end position of the bubble, it is possible to measure the transpiration rate. Capillary tube
Factors affecting transpiration • The transpiration rate of a plant can be affected by environmental conditions:- • Temperature • Humidity • Wind speed • Surface area • The transpiration rate can be increased by:- increase in temperature, increase in wind speed, increase in surface area and a decrease in humidity. • These all increase the rate of water vapour lost through the stomata of a leaf.
Right’s Respecting School: UN Convention of the Right’s of a Child • Article 15: Every child has the right to meet with other children and to join groups and organisations, as long as this doesn’t stop other people from enjoying their rights.
Investigating transpiration Aim: To investigate how light intensity affects the transpiration rate of a geranium leaf. Equipment: • Measuring cylinder, 2 glass beakers, plasticine, geranium leaf, lamp, cardboard.
Diagram: Geranium Cardboard Beakers sealed with plasticine Lamp 200ml water
Method: Day 1 • Collect your equipment. • Measure 200ml cold water using the measuring cylinder and add to one of the glass beakers. • Cut one geranium leaf. Ensure the stem is left as long as possible. • Place a small hole at the centre of a square piece of card using a sharp pencil. • Push the geranium stem through the hole and seal the hole on the top and bottom of the card using a small piece of plasticine. • Place the card and leaf on top of the beaker containing the water. Ensure that the stem of the leaf is in contact with the water. • Rest the second beaker upside down on top of the first and plug the spout openings with more plasticine. • One pair position a lamp 20cm from the beaker and switch on and one pair leave the beaker in room conditions. • Leave the apparatus overnight.
Method: Day 2 • Observe the beakers. Do you notice any changes? • Use a measuring cylinder to measure the volume of water left in the bottom beaker. • Is this volume the same as the volume at the start? Why or why not? • What has happened to the water that has been lost? • Write up your experiment in a scientific way using a title, aim, diagram, method, results table and conclusion.
Results • Group results.
Results • Class results
Conclusion • Conclusion: linked to the aim. What have the results shown us? • Evaluation: Is there anything we could improve? Could we make our results more reliable? • https://www.twigonglow.com/experiment/water-uptake-in-plants-4174/0
Exit Task C D E
Measuring transpiration Learning Intentions: To learn the structures and functions involved in the transpiration process. To learn experiments that measure the rate of transpiration. Success Criteria: Identify the structures and their function in transpiration. Identify how transpiration rate can be measured.
Past Paper Practice National 5 N5 Key Area 2.5 Plant Transport
1 • Water moves into/enters/is absorbed by root hairs by osmosis/diffusion (1) • (Water) travels upwards in the xylem (1) • (water) travels to the stomata /pores and evaporates/transpires /diffuses out (1)