Genes code for proteins. That way they determine biological structures and functions. Besides genes, the environment has the great impact on the structure of an organism. Alleles and genes will give a trait, but the environment can affect it. For example, alleles that are responsible for height will give a person some average height. But if the person begins to train basketball at the early age (during growth), the person will overcome the average height. This is the effect of the environment and not genes. The other example is that if a person lives in a sunny region, the person will be tan.
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.
The answer for this will be C an integration of organ systems this is because the endocrine system also works with the nervous system and immune system etc
A double helix is <span>a pair of parallel helices intertwined about a common axis, especially that in the structure of the DNA molecule. or in other words a double spiral.</span>
