Plant Science: An Introduction to Botany

Although our biology is significantly different than that of plants, scientists are discovering more and more similarities. We share quite a bit of DNA, thrive in moderate temperatures, have a circadian rhythm of rest and activity, require water for life, and can sense our environment and respond. Some scientists suggest that plants might even have developed a type of "hearing."

More than 425 million years ago, a group of plants called bryophytes developed two special adaptations that allowed them to inhabit dry land. Why are these early plants still so important today, both environmentally and commercially? And how does one of these most ancient species engineer its own habitat to the exclusion of more modern competitors?

Botanists still struggle to unravel the full evolutionary history of ferns, hardy plants of staggering reproductive and colonization power. With billions of lightweight spores produced by each individual and the vasculature to transport nutrients throughout the plant, ferns are found in low-light and bright-light environments from the arctic regions to the tropics.

Photosynthesis might be the "star," but what takes place under the soil is just as imperative for plant survival. In fact, the root is so important that it's the first evidence of germination in the seed. Learn how roots physically support the plant, absorb water and minerals, and store carbohydrates, almost always relying on symbiosis with bacteria and fungi.

Learn how the pressure flow hypothesis models the movement of sugars through the plant's phloem and xylem, and what plant structures determine whether the organism will grow in height, girth, or both. And while the stem functions to support the plant's branches and leaves, in some plants the stem is also the site of photosynthesis.

Plants "know" when to shed their leaves or grow new ones via the same mechanism that causes the many developmental changes in our own bodies: hormones. Learn about the hormones that affect leaf growth and abscission - and the role played by Charles Darwin in their discovery.

Green plants generate their mass - whether the mass of the smallest blade of grass or the tallest tree on Earth - by synthesizing food from carbon dioxide and water via the energy from sunlight with the help of appropriate enzymes. See how the fascinating details of photosynthesis separate the plants from the animals.

How do plants "choose" the best time to flower? Do they sense the daylight hours becoming longer in the springtime? Or do they sense the nights becoming shorter? Learn which pigments interact with sunlight to serve as chemical clocks for flowering plants and what roles are played by messenger RNA and temperature - including their part in climate change.

While spores have continued to provide effective reproduction through the millennia, evolution has led to several successful alternatives. In a little package of embryonic roots, stems, leaves, and nourishment, a seed offers the ability to lie dormant until conditions are right for the highest chance of survival. Learn about the unique properties of the cycads, gingkos, and gnetophytes.