Plants are the basis of the food pyramid for all living things, even other plants. They have always been very important to people, not only for food, but also for clothing, weapons, tools, dyes, medicines, shelter and a great many other purposes. Both humans and animals benefit from plants. We eat many different types of plants such as fruits and vegetables. We also use plants for our herbs. Plants are also used to manufacture many different products such as shampoos, rubber, paper, and camera film. In some countries, fermented sugar cane is used instead of gasoline.
Animals use plants in many different ways also. They eat many fruits and other plants. Many animals use plants for shelter. Plants also provide animals with protection from predators. The destruction of different plants sometimes leads to animals becoming endangered or extinct.
The basic structure of plants consists of roots, stem, leaves, flower and/or fruit or seeds. A flower is the part of the plant that makes the seeds. The main parts of a flower are the carpels and stamens. These parts are often found in the center of the flower. There are egg cells in the carpel and pollen cells in the stamen. All flowers have four basic parts: sepals, petals, carpels, and stamen. Different flowers have different numbers and shapes of these parts.
Most plants can be divided into one of two general categories: herbaceous or woody plants. Herbaceous plants have soft stems, while woody plants are tree-like. Herbaceous plants produce completely new stems each year. The approaching cold weather causes the new stems to die back to the ground.
Some herbaceous plants survive periods of cold by forming underground bulbs, or tubers used for food storage. Many herbaceous plants complete their life cycles within one growing season and the whole plant dies, even the roots. These annuals produce seeds that will form new plants the next year.
Land plants are divided into two groups based on whether they have vascular tissues or not.