During muscle contraction, the cross-bridge detaches when 1  ________. the myosin head binds to an ADP molecule. 2  the myosin head binds to an ATP molecule. 3  calcium ions bind to troponin. 4  calcium ions bind to actin.
A plant operator is a person who supervises the operation of an industrial plant. The term is usually applied to power plants or chemical plants such as gas extraction, petrochemical or oil refinery or other chemical processes.There may be a control room in the plant where the operator works.These are known as board operators. Generally, operators are assigned to a particular unit, on which they are responsible for a certain function or area of equipment.he term is usually applied to power plants or chemical plants such as gas extraction, petrochemical or oil refinery or other chemical processes. There may be a control room in the plant where the operator works.
Planter (farm implement) A planter is a farm implement, usually towed behind a tractor, that sows (plants) seeds in rows throughout a field.[1] It is connected to the tractor with a drawbar or a three-point hitch. Planters lay the seeds down in precise manner along rows. Planters vary greatly in size, from 1 row to 48, with the biggest in the world being the 48-row John Deere DB120. Such larger and newer planters comprise multiple modules called row units. The row units are spaced evenly along the planter at intervals that vary widely by crop and locale. The most common row spacing in the United States today is 30 inches.