Cover Page

Abstract

     Plants grow from seeds, which absorbs water from its roots. As the plants grows, proper nutrients from the soil, light and water would be required to ensure continuous growth. Plants respond to the Earth’s gravitational attraction and light via a process called gravitropism. Stems grow towards the source of light. The roots of a plant grow downward and away from light. These particular responses are called tropisms. Plants’ growth in response to gravity is known as gravitropism but the growth response to light is phototropism. Both tropisms are controlled by plant growth hormones. (Johnson,1999). Auxin is the chemical that allows for the gravitropism process. The auxin stimulates cell elongation along the stem, resulting in the stem bending upwards. (Thinkquest, 2008)