Plants are a vital part of the Earth’s ecosystem and play an important role in the global carbon cycle. They are the primary source of food for many animals, including humans, and provide us with oxygen gas to breathe. Plants also help regulate the Earth’s climate by absorbing carbon dioxide gas from the atmosphere.
There are two main types of plants: flowering plants (angiosperms) and non-flowering plants (gymnosperms). Flowering plants produce seeds that are enclosed in a protective covering, while non-flowering plants produce exposed seeds. Gymnosperms include conifers, cycads, ginkgoes, and Gnetales; angiosperms include monocots and eudicots.
Flowering plants evolved relatively recently, about 140 million years ago, and since then have become the dominant type of plant on Earth. The first flowers were small and unassuming, but over time they have diversified into the wide range of colors and shapes we see today. Flowers attract pollinators such as bees and butterflies with their color patterns and nectar production, which has led to a close relationship between these groups of organisms.
The vast majority of plant species are angiosperms, but gymnosperms still play an important role in many ecosystems. Conifers dominate boreal forests while ginkgos are common in temperate forests. Cycads can be found in tropical regions while Gnetales occur in subtropical areas. All four groups are represented in rainforests worldwide.
Plants have a variety of adaptations that allow them to thrive in different environments. For example, some desert plants have long roots that reach down deep into the soil to access water stores; other desert plants have leaves that reflect light to reduce water loss through evaporation; yet others have spines or thorns to deter herbivores from eating them. Similarly, alpine plants often have hairy leaves that protect them from cold winds; tundra plants tend to be small with shallow root systems that prevent them from being blown away by strong winds; aquatic plants usually have floating leaves or specialised roots that help them absorb nutrients from water sources; mangrove trees grow in saltwater marshes with stilt-like roots that keep them above the floods during high tide events. No matter where they live, all plants need sunlight for photosynthesis – this is how they make their own food using energy from sunlight