In a laboratory experiment you have treated a muscle cell with a calcium channel blocker. the membrane still depolarizes, but the concentration of calcium never increases in the cytosol. which of the following describes what will happen next?
a. only one cross-bridge cycle will occur but no second cycle.
b. binding of myosin to actin will take place.
c. tropomyosin will continue to cover the myosin binding sites on actin and no cross-bridges will form.
d. a single twitch in skeletal muscle but no sustained contraction.

answer; i believe its echoic memory,it is believed to last three to four seconds; good luck

the nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and dna, the building blocks of all life. plants absorb nitrogen in the form of ammonium, nitrate ion and, on rare occasions, as amino acids. animals receive nitrogen necessary for biological processes from feeding on living or dead organic matter.