There are three types of muscle tissue<span>: Visceral, </span>cardiac<span>, and </span>skeletal<span>. </span>Visceral Muscle<span>. </span>Visceral muscle<span> is found inside of organs like the </span>stomach<span>, intestines, and </span>blood vessels. The major types of muscle systems are the skeletal muscles, cardiac muscles and smooth muscles.<span> The skeletal muscles are voluntary muscles, whereas the smooth and cardiac muscles are involuntary ones.</span>
The double helix is a description of the molecular shape of a double-stranded DNA molecule. In 1953, Francis Crick and James Watson first described the molecular structure of DNA, which they called a "double helix," in the journal Nature.
