Answer:
The commercial application of ethylene gas are as follows:
The ethylene gas are important for the early ripening of fruits.
The elongation of shoot can be done by ethylene gas.
The flower stimulation and swelling of stem can be achieved by the use of ethylene gas.
The leaf abscission of ornamental plants can be done by the use of ethylene hormone.
It is the circulatory system and respiratory system.
Coefficients of Absorption for Common Materials
Perforated acoustic ceiling material 60%
Heavy curtains 50%
Carpeting 20%
Wood 5%
Plaster 3%
Clay tile 3%
Concrete 2%
The answer is C. Heavy curtains
Striated muscles contain repeating sarcomeres of overlapping arrays of long, thin actin and thicker myosin filaments. Myosin filaments contains the myosin heads, which are enzymes that can bind to actin, split and make use of the energy from ATP. When muscle contraction starts, myosin heads bind to actin, change their configuration on actin, liberating the products of ATP hydrolysis and causing slide of the actin and myosin filaments. The action of the proteins troponin and tropomyosin on the actin filaments regulates vertebrae striated muscle contraction. The release of calcium ions from the sarcoplasmic reticulum is triggered by the nervous stimulation which causes depolarization of muscle membrane. Calcium ions bind to troponin and thus cause or allow the tropomyosin strands on the actin filament to move so that the part of the actin surface where myosin heads need to bind is uncovered. Contraction then occurs and only stops when the sarcoplasmic reticulum pumps calcium out of the muscle interior.
So basically, what triggers the uncovering of the myosin binding site on actin is the calcium ions binding to troponin and changing configuration.
