Some ways in which communicable diseases spread are by: physical contact with an infected person, such as through touch (staphylococcus), sexual intercourse (gonorrhea, HIV), fecal/oral transmission (hepatitis A), or droplets (influenza, TB) travel through the air, such as tuberculosis or measles.
Circulatory system pumps blood from the heart to the lungs to get oxygen. The heart then sends oxygenated blood through arteries to the rest of the body. The veins carry oxygen-poor blood back to the heart to start the circulation process over. Your circulatory system is critical to healthy organs, muscles and tissues.
D)all of the above
<span>Homeostasis is the property of a system, either open or closed, that regulates its internal environment and tends to maintain a stable, constant condition within an organism. (Eg controlling amount of sugar in the bloodstream, keeping waste levels at acceptable levels.) </span>
<span>Opening and closing stomata controls the gas levels within the plant. </span>
<span>Converting excess sugar molecules to a lesser number of starch molecules regulates sugar levels. </span>
<span>Excreting waste through the cell membrane prevents waste build-up.</span>
The energy released is used for assembly of actin filament with myosin head. when myosin is attached to ATP its heads cannot bind to actin and therefore muscle will remain in relaxed form. However during muscle contraction an enzyme referred to as ATPase hydrolyses ATP to ADP and organic phosphate in the process releasing energy. The energy released changes the position of head of myosin which facilatate its binding with actin. Myosin moves towards m-line dragging actin along with it reducing the length of sarcomere leading to muscle contraction.
