Most plants follow the same basic structural patterns and have the same elements in common. Many plants have modified a part of their structure to better compete in their environment or to ward off predation by animals and insects but they all tend to follow the same basic formula. Plants are a critical basic building block in the food chain because of their ability to convert light energy into food and convert carbon dioxide in to oxygen.
Roots are responsible for supporting the plant in the ground and taking in nutrients and water from the soil. Large trees need large root structures to keep from toppling over in high winds. Some climbing plants use roots to cling to the surface of a tree or wall. Modified roots like tubers and bulbs also serve as storage for excess food or as a source of nutrients for the next growing season.
The stems of a plant supports the leaves and arranges them so that they are all facing the light source in the most efficient way. They also transport water up the plant from the roots and food down the stem from the leaves. Stems also have the ability to move with the light source by concentrating hormones on the dark side of the stem, causing it to grow slightly faster, which makes a leaf bend toward the light.
Leaves are primarily food manufacturing organs from the plant. They collect light and atmospheric carbon dioxide, combine it with water, then convert it to simple sugars using photosynthesis. They also release oxygen and water vapor into the air as a by product. Leaves can be single or compound, meaning they are made of several leaflets, but they all serve as the main food production source for the plant. In some plants, like a Venus flytrap, the tips of the leaves are modified to catch insects, which they dissolve and absorb to supplement the lack of nutrients in their habitat. Other modified leaves include colored leaves meant to look like petals to attract pollinators, or tendrils used by a climbing vine to anchor themselves on a trellis.
The purpose of a flower is reproduction. This is where pollination, then fertilization of the undeveloped ovaries happens. They usually consist of the male organs which contain the pollen and the female organs which contain the undeveloped eggs. Some plants have both male and female parts in one flower, while others have separate male and female flowers to prevent self pollination. The primary function of scent, petals and nectar are to attract potential pollinators.
The fruit is the ripened ovary of a flower that contains the seeds. After fertilization the flower dies off and the walls of the ovary swell. The ripened ovary walls serve to protect the seeds from predation or to provide an incentive to an animal or insect to eat the fruit and then transport the seeds to another location.