View source for Plant Hormone

==Key Stage 4 Foundation==
===Meaning===
'''Plant hormones''' are chemical messengers ([[hormone]]s) which affect the growth of a [[plant]].

===About Plant Hormones===
: '''Plant hormones''' may cause [[Plant Cell|cells]] in the [[plant]] to elongate or divide.
: The response of a [[plant]] to [[light]] and [[gravity]], known as [[phototropism]] and [[gravitropism]], is controlled by the '''plant hormone''' [[auxin]].

==Key Stage 4 Higher==
===Meaning===
'''Plant hormones''' are chemical messengers ([[hormone]]s) which affect the growth of a [[plant]].

===About Plant Hormones===
: '''Plant hormones''' may cause [[Plant Cell|cells]] in the [[plant]] to elongate or divide.
: The response of a [[plant]] to [[light]] and [[gravity]], known as [[phototropism]] and [[gravitropism]], is controlled by the '''plant hormone''' [[auxin]].
: The [[germination]] of [[seed]]s is controlled by a group of '''plant hormones''' called [[gibberellin]]s.
: [[Gibberellin]]s also stimulate the growth of the [[plant]] [[stem]] and [[fruit]].
: The ripening of [[fruit]] is controlled by [[ethene]].
: [[Ethene]] also affects the rate of [[Cell Division|cell division]].

===Using Plant Hormones===
====Auxin====
: Gardeners use [[auxin]] to encourage cuttings of [[plant]]s to grow new [[root]]s when they are planted.
: [[Auxin]] can be used to kill [[plant]]s by causing them to grow too fast, using up their stores of [[energy]]. Since auxin is sprayed on [[leaf|leaves]], [[plant]]s with larger [[leaf|leaves]] will [[Absorb (Biology)|absorb]] more and are more likely to die.
====Gibberellins====
: Farmers use [[gibberellin]]s to cause [[seed]]s to [[germinate]]. This can help them all grow at the same time, making it easier to harvest them all at once.
: [[Gibberellin]]s are also used to make [[fruit]] grow faster.
====Ethene====
: To make [[fruit]] last longer they are harvested before they are ripe. When the farmer wants to sell them they put [[ethene]] [[gas]] in their container causing them to ripen.


===References===
====AQA====

:[https://www.amazon.co.uk/gp/product/0008158754/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158754&linkCode=as2&tag=nrjc-21&linkId=27ad53b0283feeff7fc5ae04a9e205f431 ''Plant hormones, pages 171, 220-5, GCSE Biology; Student Book, Collins, AQA '']

====Edexcel====

:[https://www.amazon.co.uk/gp/product/1292120207/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120207&linkCode=as2&tag=nrjc-21&linkId=22455ff53961978667722edaa64c0be5 ''Plant hormones, pages 136-137, GCSE Biology, Pearson, Edexcel '']
:[https://www.amazon.co.uk/gp/product/1292120207/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120207&linkCode=as2&tag=nrjc-21&linkId=22455ff53961978667722edaa64c0be5 ''Plant hormones; uses, pages 138-139, GCSE Biology, Pearson, Edexcel '']