Why discuss the structure and function of plants?
Plants are as essential to human existence as land, water, and air. Without plants, our day-to-day lives would be impossible because without oxygen from photosynthesis, aerobic life cannot be sustained. From providing food and shelter to serving as a source of medicines, oils, perfumes, and industrial products, plants provide humans with numerous valuable resources.
When you think of plants, most of the organisms that come to mind are vascular plants. These plants have tissues that conduct food and water, and most of them have seeds. Seed plants are divided into gymnosperms and angiosperms. Gymnosperms include the needle-leaved conifers—spruce, fir, and pine—as well as less familiar plants, such as ginkgos and cycads. Their seeds are not enclosed by a fleshy fruit. Angiosperms, also called flowering plants, constitute the majority of seed plants. They include broadleaved trees (such as maple, oak, and elm), vegetables (such as potatoes, lettuce, and carrots), grasses, and plants known for the beauty of their flowers (roses, irises, and daffodils, for example).
While individual plant species are unique, all share a common structure: a plant body consisting of stems, roots, and leaves. They all transport water, minerals, and sugars produced through photosynthesis through the plant body in a similar manner. All plant species also respond to environmental factors, such as light, gravity, competition, temperature, and predation.
The roots, stems, and leaves of plants are also structured to ensure that a plant can obtain the required sunlight, water, soil nutrients, and oxygen resources. Plants have developed some remarkable adaptations to thrive in less than ideal habitats, where one or more of these resources is in short supply.
In tropical rainforests, light is often scarce, since many trees and plants grow close together and block much of the sunlight from reaching the forest floor. Some plants have special adaptations that help them to survive in nutrient-poor environments. Many swamp plants have adaptations that enable them to thrive in wet areas, where their submerged roots have low access to oxygen. What type of adaptations do you think would help plants in these conditions?
Learning Outcomes
- Identify basic common structures of plants
- Describe how water and solutes are transported in plants
- Identify common sensory systems and responses in plants
- Identify the key elements and processes in plant growth
- Discuss the common nutritional needs of plants
