The twins Mike and Mary are fascinated by jungles after learning about them. They ask their mother if they can make a plant jungle at home. Their mother thinks it may be possible. The document then provides instructions on how to create a plant jungle by putting soil and compost in a plastic jar, planting lettuce and bean seeds, watering them, and observing their growth over weekly periods. Key factors for plant growth like water, light, soil, temperature, oxygen, carbon dioxide, and minerals are also explained.