Photograph by Rich Reid. Tundras are among Earth's coldest, harshest biomes. Tundra ecosystems are treeless regions found in the Arctic and on the tops of mountains, where the climate is cold and windy and rainfall is scant. Tundra lands are snow-covered for much of the year, until summer brings a burst of wildflowers.
Muscle is a soft tissue found in most animals. Muscle cells contain protein filaments of actin and myosin that slide past one another, producing a contraction that changes both the length and the shape of the cell. The statement that the tongue is the strongest muscle in the body appears frequently in lists of surprising facts, but it is difficult to find any definition of strength that would make this statement true. 2  Note that the tongue consists of eight muscles, not one.
Muscle is a bundle of tissue that is capable of contracting. The primary functions of muscles are to generate force and cause motions. Your body has more than 600 different types of muscles. Muscles also contribute to 40 to 50 percent of your weight. Some muscles can be controlled consciously, while others are controlled automatically by your ...keletal Muscle. When people talk about muscles, they are usually referring to skeletal muscle. This type of muscle is attached to your bones through tendons, and it is the most abundant tissue in your body. The contraction of skeletal muscle causes the diverse movements of your skeleton.