Kids Research Express

Foxglove Plant The common foxglove is grown for decorative and medicinal purposes. The flowers contain glycosides (chemicals that affect heartbeat and pulse), which can be extracted from the leaves and used to regulate and strengthen a person’s heartbeat. However, if plant materials containing glycosides are directly consumed by humans, nausea, abdominal pain, diarrhea, and heartbeat and pulse abnormalities can result. If consumed in large enough quantities, glycosides can cause convulsions and death.

The lichen seen here growing on a tree is one of the fruticose lichens. It is made up of a layer of algal cells, a middle layer of fungal hyphae, and an outer layer of fungal tissue. Lichen, living partnership of a fungus and an alga . The fungus component is called the mycobiont and is composed of intertwined, threadlike fibers called hyphae that are tightly packed into a tissuelike sheet. The fungus uses these hyphae to absorb food from its surroundings. The algal component, called the photobiont, makes its own food through photosynthesis and grows as a mass of green cells dispersed among the fungal hyphae. Lichens survive in a wide variety of environments, either forming small, circular crusts or leaflike structures attached to bark, rocks, or soil, or as hairlike structures hanging from tree branches. A lichen is actually a combination of two separate organisms: an alga and a fungus. Most lichens are three-layered organisms, with an algal layer sandwiched between two

Algae, diverse group of simple, plantlike organisms. Like plants, most algae use the energy of sunlight to make their own food, a process called photosynthesis . However, algae lack the roots, leaves, and other structures typical of true plants. Algae are the most important photosynthesizing organisms on Earth. They capture more of the sun’s energy and produce more oxygen (a byproduct of photosynthesis) than all plants combined. Algae form the foundation of most aquatic food webs , which support an abundance of animals. Algae vary greatly in size and grow in many diverse habitats. Microscopic algae, called phytoplankton, float or swim in lakes and oceans. Phytoplankton are so small that 1000 individuals could fit on the head of a pin (see Plankton ). The largest forms of algae are seaweeds that stretch 100 m (300 ft) from the ocean bottom to the water’s surface. Although most algae grow in fresh water or seawater, they also grow on soil, trees, and animals, and even under or ins