Page 1: Plant Hormones and Growth Responses

The page explores how plants coordinate their growth through hormonal control, particularly focusing on tropisms and specific plant hormones. The content details the mechanisms of auxins, gibberellins, and ethene in controlling plant growth and development.

Definition: Tropisms are directional growth responses of plants to specific environmental stimuli such as light or gravity.

Vocabulary: Auxins are plant growth hormones produced in shoots and roots that control directional growth responses.

Example: During phototropism, auxin accumulates on the shaded side of shoots, causing cells to elongate faster and the shoot to bend towards light.

Highlight: The concentration of auxins produces opposite effects in shoots and roots - stimulating growth in shoots but inhibiting growth in roots.

Quote: "Gibberellins are hormones that are important for starting the germination of seeds."

The page explains how negative geotropism in plants occurs in shoots, while roots exhibit positive geotropism. Similarly, shoots demonstrate positive phototropism while roots show negative phototropism. This differential response helps optimize plant growth and development. The text also includes practical applications, explaining how auxins are used in agriculture and horticulture through their growth-regulating properties.