Fruit-bearing plants generally start out as fruit themselves. The structure of fruit is adapted so that it functions as a means to disperse seeds so that they can sprout and grow into new fruit-bearing plants. Most fruit has a thin skin, a meaty flesh that is good to eat and seeds at the core. The means of dispersal may be through animals, wind, water or even explosion.
A seed is a package that contains everything a plant needs to begin life. Each seed typically contain the embryo of a new plant, along with the nutrients that it needs to germinate and grow contained in a hard shell. When the conditions are right for the plant to grow, the seed's roots, stem and first leaves emerge from the hard shell.
When the seed first emerges from its shell and breaks free of the soil, it is known as a sprout. As the sprout grows and more leaves begin to emerge, it is known as a seedling. The seedling will change to a young adult plant as branches begin to grow from the seedling and develop leaves of their own. When a plant reaches adulthood, it is able to produce fruits and seeds of its own.
The process of sexual reproduction is what leads a plant to produce fruits and seeds of its own. In the first step of this process, a fruit-bearing plant will produce flowers. The flowers have several distinctive parts, including stamens, which are male reproductive parts that bear pollen; a pistil, which is the female reproductive organ; and petals to attract pollen-bearing insects such as bees and birds such as the hummingbird. The flower may also contain nectar to attract insects and birds.
The pistil contains a stigma at the end, which is covered by a sticky substance to trap and hold pollen. When pollen sticks to the stigma, the flower creates a pollen tube through the pistil from the stigma to the ovary to pull sperm from the pollen and fertilize the flower's egg to create a seed. Fruit grows around the seed, and gradually the flower petals are pushed out by the fruit.
Because there are so many threats to seeds and seedlings, a plant will produce many seeds and much fruit to ensure that some of its offspring survive. Animals such as birds, squirrels, bears, deer and even humans eat the fruit and either discard the seeds or pass them through their digestive tracts and deposit them elsewhere. The trip through an animal's digestive tract is often required to soften the shell of a seed enough for it to sprout a new plant.