OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Why do gardeners use rooting powder?

1. It helps prevent diseases

2. It contains the growth hormone auxin

3. It increases the soil nutrients

4. It protects plants from insects

The correct answer is: It contains the growth hormone auxin

Gardeners use rooting powder primarily because it contains the growth hormone auxin, which plays a vital role in promoting root development in plants. Auxins are a group of hormones that regulate various aspects of plant growth. When applied to cuttings, rooting powder encourages the formation of new roots, increases the rate at which roots grow, and establishes a successful plant more quickly. The effectiveness of rooting powder is rooted in its ability to stimulate cell division and elongation in the area of application, making it particularly beneficial for propagating new plants from cuttings. As new roots develop, the plant can better absorb water and nutrients, leading to healthier and more robust growth. While other options mention aspects such as disease prevention, soil nutrient enhancement, and pest protection, they do not directly relate to the primary function of rooting powder, which is focused on enhancing root growth through the action of auxins.