Tropical rain forests are characterized by dense vegetation, seasonally warm temperatures, and abundant rainfall. A great variety of plants can be found in tropical rain forests. Enormous trees as tall ... Read More

Asters are radial microtubule arrays, in animal cells, which are located around each pair of centrioles. They appear to be shaped like a star and are involved in the cleavage ... Read More

Viewing animals and wildlife in action can be enjoyable and fascinating. About's Animals/Wildlife guide has a collection of wildlife images ranging from spooky looking spiders to elegant birds in flight. Visit ... Read More

Look carefully at the picture. Can you see the bird hidden in the shrubbery? With predators always on the lookout for a meal, prey must constantly avoid being eaten. Any adaptation ... Read More

Taigas, also called boreal or coniferous forests, are forests of dense evergreen trees that extend across North America, Europe, and Asia. Taiga winters are long and harsh with temperatures averaging ... Read More

The cardiac cycle is the sequence of events that occur when the heart beats. In the systole phase of this cycle, the ventricles contract pumping blood into the arteries. Systole Phase: The ... Read More

With the help of a video game, researchers show that hand coordination is managed in the brain by appointing one hand the "leader" and the other the assistant. The study, published ... Read More

Cell division is a process that enables organisms to grow and reproduce. Dividing cells go through an ordered series of events called the cell cycle. Mitosis is a phase of the ... Read More

Centrioles are cylindrical structures that are composed of groupings of microtubules arranged in a 9 + 3 pattern. Centrioles replicate in the interphase stage of mitosis. They help to organize the ... Read More

Savannas are areas of open grassland with very few trees. There are two types of savannas, tropical and semi-tropical savannas. Savannas are typically dry, receiving less than 30 inches of ... Read More

Spindle fibers are aggregates of microtubules that move chromosomes during cell division. Spindle fibers form at opposite poles of a cell during prophase. During metaphase, spindle fibers extend from the cell ... Read More

Researchers have developed a new treatment for people who suffer from ulcers. The treatment, levofloxacin-based triple therapy, was found to be more effective in ulcer patients than current therapies. The findings from ... Read More

The tundra biome is characterized by extremely cold temperatures and treeless, frozen landscapes. There are two types of tundra, the arctic tundra and the alpine tundra. The arctic tundra is ... Read More