Changes

| style="height:20px; width:200px; text-align:center;" |These are the '''leaves''' on a [[Horse Chestnut Tree]].| style="height:20px; width:200px; text-align:center;" |This is a '''leaf''' from a [[Beech Tree]]| style="height:20px; width:200px; text-align:center;" |This is an [[Oak Tree]] '''leaf'''.

| style="height:20px; width:200px; text-align:center;" |3 '''leaves''' from an [[Ash Tree]].| style="height:20px; width:200px; text-align:center;" |A [[Silver Birch Tree]] '''leaf'''.| style="height:20px; width:200px; text-align:center;" |These are the '''leaves''' of a [[Cedar Tree]]

| style="height:20px; width:200px; text-align:center;" |These are the '''leaves''' of a [[Fir Tree]].| style="height:20px; width:200px; text-align:center;" |These [[Pine Tree]] '''leaves''' are called Pine Needles.| style="height:20px; width:200px; text-align:center;" |These are the '''leaves''' of a [[Holly Tree]].

An ==Key Stage 2=====Meaning===The leaf is an [[organ]] in a [[plant]] used to make food by [[photosynthesis]]. ===Adaptations===: The '''leaf''' is often wide and thin to collect as much sunlight as possible. The more sunlight it collects the more food it can make.: The '''leaf''' has tubes called 'veins' inside it which carry the food away from the '''leaves''' to the [[root]]s and [[flower]] and to carry [[water]] into the '''leaf''' from the [[root]]s. ==Key Stage 3=====Meaning===[[File:LeafCrossSection.png|right|300px|thumb|A cross section of a [[leaf]].]]A [[leaf]] is an [[organ]] in the [[Shoot System|shoot system]] of a [[plant]] that uses [[photosynthesis]] to [[Producer|produce]] food for the [[plant]]. ===About Leaves===: The [[Cell (Biology)|cells]] in '''leaves''' have many [[chloroplast]]s inside them for [[photosynthesis]].: '''Leaves''' produce food that is sent to the [[root]]s through the [[phloem]] which is part of a [[Plant Vein|plant vein]] that carries sap.'''Leaves''' have many tissues inside them found in layers:*Upper Epidermis - A layer of cells at the top of the leaf that make a waxy cuticle on top to keep the [[leaf]] waterproof.*[[Palisade Tissue]] - A layer of [[Palisade Cell|palisade cells]] which have lots of chloroplasts in them for [[photosynthesis]].*[[Spongy Mesophyll Tissue]] - A layer of [[Spongy Mesophyll Cell|spongy mesophyll cells]] that have irregular shapes to allow [[air]] to pass through the [[leaf]].*Lower Epidermis - A layer of [[Cell (Biology)|cells]] at the bottom of the [[leaf]] with [[Stoma|stomata]] to allow [[air]] into and out of the [[leaf]].{| class="wikitable"|-|[[File:LeafCrossSectionDiagram.png|center|600px]]|-| style="height:20px; width:600px; text-align:center;" |A [[diagram]] of the cross section of a [[leaf]] showing [[Palisade Cell]]s, [[Spongy Mesophyll Cell]]s and [[Guard Cell]]s.|} ===Adaptations of Leaves===: '''Leaves''' have a waxy cuticle to stop [[water]] escaping.: '''Leaves''' contain [[Cell (Biology)|cells]] with many [[chloroplast]]s for [[photosynthesis]].: '''Leaves''' have [[air]] gaps between the [[Spongy Mesophyll Cell|spongy mesophyll cells]] to allow [[Gas Exchange in Plants|gas exchange]].: '''Leaves''' usually have more [[Guard Cell|guard cells]] and [[Stoma|stomata]] on the underside (lower epidermis) than the top side (upper epidermis). These close when the [[leaf]] gets [[dehydrate]]d, stopping [[Carbon Dioxide|carbon dioxide]] getting into the [[leaf]] which stops them using [[water]] for [[photosynthesis]]. {| class="wikitable"|-|[[File:Stomata.png|center|400px]]|-| style="height:20px; width:400px; text-align:center;" |The under side of a [[leaf]] showing [[Guard Cell|guard cells]] and [[Stoma|stomata]].|} ==Key Stage 4=====Meaning===A [[leaf]] is an [[organ]] in the [[Shoot System|shoot system]] of a [[plant]] that uses [[photosynthesis]] to [[Producer|produce]] food for the [[plant]]. ===About Leaves===: The [[Cell (Biology)|cells]] in '''leaves''' have many [[chloroplast]]s inside them for [[photosynthesis]].: '''Leaves''' produce food that is sent to the [[root]]s through the [[phloem]] by [[translocation]].'''Leaves''' have many [[tissue]]s inside them found in layers:*Upper Epidermis - A layer of cells at the top of the leaf that make a waxy cuticle on top to keep the [[leaf]] waterproof.*[[Palisade Tissue]] - A layer of [[Palisade Cell|palisade cells]] which have lots of chloroplasts in them for [[photosynthesis]].*[[Spongy Mesophyll Tissue]] - A layer of [[Spongy Mesophyll Cell|spongy mesophyll cells]] that have irregular shapes to allow [[air]] to pass through the [[leaf]].*Lower Epidermis - A layer of [[Cell (Biology)|cells]] at the bottom of the [[leaf]] with [[Stoma|stomata]] to allow [[air]] into and out of the [[leaf]].{| class="wikitable"|-|[[File:LeafCrossSectionDiagram.png|center|600px]]|-| style="height:20px; width:600px; text-align:center;" |A [[diagram]] of the cross section of a [[leaf]] showing [[Palisade Cell]]s, [[Spongy Mesophyll Cell]]s and [[Guard Cell]]s.|} ===Adaptations for Photosynthesis===: '''Leaves''' are usually wide and thin to provide a large area to collect sunlight.: '''Leaves''' contain [[Cell (Biology)|cells]] with many [[chloroplast]]s for [[photosynthesis]].: '''Leaves''' have [[air]] gaps between the [[Spongy Mesophyll Cell|spongy mesophyll cells]] to allow [[Gas Exchange in Plants|gas exchange]].: [[Xylem Tissue]] transports [[water]] to the '''leaves''' for [[photosynthesis]].: '''Leaves''' have [[Guard Cell|guard cells]] around a [[stoma]] which closes when the [[leaf]] gets [[dehydrate]]d, stopping [[Carbon Dioxide|carbon dioxide]] getting into the [[leaf]]. This stops them using [[water]] for [[photosynthesis]] and helps protect the plant from further dehydration.: '''Leaves''' usually have more [[Guard Cell|guard cells]] and [[Stoma|stomata]] on the underside (lower epidermis) than the top side (upper epidermis) because [[stoma|stomata]] on the top side would lose [[water]] more quickly, increasing the rate of dehydration.