2.6 Hormones and the Control of Plant Growth Some words may be used more than once; some may not be used at all. Auxin Minerals Towards Gravity Growth Different Most Least Same Light Respond Away Lower Unevenly Gravitropism Photosynthesis Phototropism Sensitive Evenly Water How do plants respond to their environment? Plants are …………………….to their environment and can ………………………..to it. For plant roots to grow downwards they must grow towards ………………….. which directs it towards the ……………….. and minerals that the roots need to absorb. For plant shoots to grow upwards they must grow towards the …………………and against the force of………………….. This allows them to absorb more light so they can ……………………… as much as possible. The response of a plant to light is called…………………….. The response of a plant to gravity is called……………………….. What causes the roots and shoots to grow in a particular direction, to bend? If one side of a root or shoot grows quicker than the other, the shoot or root will bend ……………….from that area. If this side grows quicker than the other…. It will end up looking like this The response of plants to light, gravity and water is controlled by a hormone called …………….. The auxin affects the rate of ………………. when it becomes …………………..distributed throughout the roots and shoots and this causes the bending described above when How does auxin cause the growth of root and shoot to occur in different directions? A normal young bean seedling is placed on its side in the dark. Auxin is equally spread throughout the tissues. Root Auxin gathers on the ………………. side of the root. Shoot Auxin gathers on the ………………side of the shoot. The root grows more on the side with the ………….. auxin. This causes the root to grow downwards towards the force of gravity. The shoot grows more on the side with the ………….. auxin. This causes the shoot to grow upwards towards the light. How will you remember this information and not get it confused? When they have grown up or down, the auxin distributes itself …………….. throughout the tissues so growth is equal throughout the root or shoot and it grows straight. 2.6 Hormones and the Control of Plant Growth Some words may be used more than once; some may not be used at all. Auxin Minerals Towards Gravity Growth Different Most Least Same Light Respond Away Lower Unevenly Gravitropism Photosynthesis Phototropism Sensitive Evenly Water How do plants respond to their environment? Plants are sensitive to their environment and can respond to it. For plant roots to grow downwards they must grow towards gravity which directs it towards the water and minerals that the roots need to absorb. For plant shoots to grow upwards they must grow towards the light and against the force of gravity. This allows them to absorb more light so they can photosynthesis as much as possible. The response of a plant to light is called phototropism. The response of a plant to gravity is called gravitropism. What causes the roots and shoots to grow in a particular direction, to bend? If one side of a root or shoot grows quicker than the other, the shoot or root will bend away from that area. If this side grows quicker than the other…. It will end up looking like this The response of plants to light, gravity and water is controlled by a hormone called auxin. The auxin affects the rate of growth when it becomes unevenly distributed throughout the roots and shoots and this causes the bending described above when How does auxin cause the growth of root and shoot to occur in different directions? A normal young bean seedling is placed on its side in the dark. Auxin is equally spread throughout the tissues. Root Auxin gathers on the bottom side of the root. Shoot Auxin gathers on the bottom side of the shoot. The root grows more on the side with the least auxin. This causes the root to grow downwards towards the force of gravity. The shoot grows more on the side with the most auxin. This causes the shoot to grow upwards towards the light. How will you remember this information and not get it confused? When they have grown up or down, the auxin distributes itself evenly throughout the tissues so growth is equal throughout the root or shoot and it grows straight.
