The basic structure of a muscle fiber is comprised of actin and myosin protein chains that straddle each other in a fusiform arrangement. The actin and myosin arrays interlock and move past each other to cause contraction of the muscle. They then move back to their initial positions in relaxation. This gives muscles their elasticity and distensibility. The muscle fibers are bundled, in their 10s to 100s up into myofibrils around an endomysium. Many myofibrils are also bound up in a perimysium to form a muscle fiber.
In order for cells to function and survive, their organelles work together to carry out specific tasks and perform specific roles.
Answer:
Krill
Explanation:
All animals in the Antarctic depend on krill, very small crustaceans, for their survival.
Answer:
Differences in temperature or precipitation determine the types of plants that grow in a given area (Figure 1). Generally speaking, height, density, and species diversity decreases from warm, wet climates to cool, dry climates. Raunkiaer (1934) classified plant life forms based on traits that varied with climate.
Explanation:
