Excitation-contraction coupling refers to the series of events that begins with the excitation of the sarcolemma in response to stimulation by a neurotransmitter, and results in the release of calcium ions from the sarcoplasmic reticulum.
Hence, option D is the 1st process that starts the excitation-contraction coupling.
Answer: Metabolic alkalosis
Explanation: Metabolic alkalosis refers to a metabolic condition in which the tissue’s pH is increased above the normal range (7.35–7.45). This occurs as a result of decrease in the concentration of Hydrogen ion, which results to increased bicarbonate in the body system. It can also be caused by direct increase in the bicarbonate concentrations.
A karyotype is an organized profile of a person's chromosomes. Two chromosomes specify sex, XX for female and XY for male. The rest are arranged in pairs, numbered 1 through 22, from largest to smallest. This arrangement helps scientists quickly identify chromosomal alterations that may result in a genetic disorder.
The option which would most likely result in the greatest decrease in the rate of a chemical reaction is adding an enzyme inhibitor to a reaction catalyzed by an enzyme.
Enzyme inhibitor is known for slowing down any processes, especially when it comes to chemical reactions, so I'd say A is the correct answer.
The number of electrons in the outermost shell of an atom
