Difference between revisions of "Gas Exchange in Plants"

Revision as of 10:10, 18 September 2018

Key Stage 3

Meaning

The gas exchange system in plants allows them to absorb and release both Oxygen and Carbon Dioxide.

About Gas Exchange in Plants

Unlike animals plants do both respiration and photosynthesis. This means sometimes they take in more Oxygen and release more Carbon Dioxide and other times they take in more Carbon Dioxide and release more Oxygen. Overall a plant makes more Oxygen than Carbon Dioxide.


During the day time the sunlight allows the plant to photosynthesize so it takes in more Carbon Dioxide and releases more Oxygen than it needs for respiration.	During the night time where there is no light, photosynthesis cannot happen but the cells still need to respire so the plant takes in more Oxygen and releases more Carbon Dioxide.

Gas Exchange in the Leaf


A diagram of the cross section of a leaf.

Leaves have air gaps between the spongy mesophyll cells to allow gas exchange.

Leaves usually have more guard cells and stomata on the underside (lower epidermis) than the top side (upper epidermis). These close when the leaf gets dehydrated, stopping carbon dioxide getting into the leaf which stops them using water for photosynthesis.


The under side of a leaf showing guard cells and stomata.

@@ Line 5: / Line 5: @@
 ===About Gas Exchange in Plants===
 : Unlike [[animal]]s [[plant]]s do both [[respiration]] and [[photosynthesis]]. This means sometimes they take in more [[Oxygen]] and release more [[Carbon Dioxide]] and other times they take in more [[Carbon Dioxide]] and release more [[Oxygen]]. Overall a [[plant]] makes more [[Oxygen]] than [[Carbon Dioxide]].
-: During the day time the sunlight allows the plant to [[photosynthesis|photosynthesize]] so it takes in more [[Carbon Dioxide]] and releases more [[Oxygen]] than it needs for [[respiration]].
-: During the night time where there is no light, [[photosynthesis]] cannot happen but the cells still need to [[respiration|respire]] so the plant takes in more [[Oxygen]] and releases more [[Carbon Dioxide]].
+{| class="wikitable"
+|-
+|[[File:Daytime.png|center|300px]]
+|[[File:Nighttime.png|center|300px]]
+|-
+| style="height:20px; width:300px; text-align:center;" |During the day time the sunlight allows the plant to [[photosynthesis|photosynthesize]] so it takes in more [[Carbon Dioxide]] and releases more [[Oxygen]] than it needs for [[respiration]].
+| style="height:20px; width:300px; text-align:center;" |During the night time where there is no light, [[photosynthesis]] cannot happen but the cells still need to [[respiration|respire]] so the plant takes in more [[Oxygen]] and releases more [[Carbon Dioxide]].
+|}
+===Gas Exchange in 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.
+| style="height:20px; width:600px; text-align:center;" |A [[diagram]] of the cross section of a [[leaf]].
 |}
-===Adaptations of Leaves===
-: '''Leaves''' have a [[Waxy Cuticle|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]].