Identify two companions group of plants and what are the symbiosis between them?

Companion planting is a method of cultivation where plants are grown together for mutual benefit. Here are two examples:

1. Corn, Beans, and Squash: This is a classic example of companion planting, often referred to as the "Three Sisters". The corn provides a structure for the beans to climb, the beans provide the nitrogen to the soil that the other plants utilize, and the squash spreads along the ground, blocking the sunlight and preventing weeds. The squash leaves also act as a "living mulch", creating a microclimate to retain moisture in the soil, and the prickly hairs of the vine deter pests.

2. Tomatoes and Basil: These two plants are often grown together because they benefit each other. Basil can repel pests that are harmful to tomatoes, and some gardeners believe that growing basil alongside tomatoes improves the flavor of the tomatoes.

In both examples, the symbiosis is mutualistic, meaning both plants in each pair benefit from the other. The corn and beans in the first example have a symbiotic relationship because the beans enrich the soil with nitrogen, which benefits the corn. The tomatoes and basil also have a mutualistic relationship because the basil repels pests that could harm the tomatoes, and the tomatoes may provide a microclimate that benefits the basil.