Ask Mr. Smarty Plants

How did you get elected class question-answerer? If you and your classmates will learn something about doing research from this, we will be pleased.

To begin with, you need to understand that all living things, plants, people and animals have a strong need to reproduce themselves. Plants do this in two ways-by blooming and making seed and by preserving nutrition in a root to come back in the Spring. Some plants, like mosses and ferns, do not bloom but they still make provisions for reproduction. Plants whose roots die in the winter and reproduce solely from seeds are called annuals. It takes a lot of energy for a plant to produce blossoms and then seeds, and once they have done so, when the weather turns cold, they usually die, root and all. Plants that can come up from a root or bulb, after the upper part of the plant has died back, are called perennials. These plants can, and most do, also produce seeds, but they have fleshy root structures that not only bring in nutrients and water for the plant from the soil, but also store nutrients to permit the plant to regrow in the same place when the weather warms up. 

First, let's talk about the annual plants that depend entirely on seeds for propagation. From everybody's favorite research site, Wikipedia, here is an article on annual plants. 

Next, perennial plants. Again, from Wikipedia, here are some useful facts on perennial plants. Some perennials, like trees and shrubs, even evergreen vines, do not die back to the ground in the winter, but the word "perennial" is usually used when speaking of herbaceous blooming plants. 

Since you asked specifically about bulbs, here is an article from Virginia Cooperative Extension Flowering Bulbs: Culture and Maintenance. Technically, tubers, bulbs and corms are stem tissues that are swollen to contain the necessary plant structures to recreate the same plant come Spring. 

From Google:

Pictures of bulbs

Pictures of roots

Pictures of tubers