C. 60 seconds. Heart rate is measured in beats per minute.
The correct order of living units from smallest to largest are: 1) Molecule 2) Organelle 3) Cell 4) Tissue 5) Organism 6) Population.
A molecule<span> is the smallest particle in a chemical element that has the chemical properties of that element or compound.
</span>An organelle<span> is a tiny cellular structure that performs specific functions within a cell. Meaning they are smaller than cells.
A cell </span><span>contains the fundamental molecules of life and of which all living things are composed of.
</span>Tissue is <span>a group of cells found together in the body.
Organisms are made up of organs, which are made up of tissues. It </span><span>is a living thing that can function on its own.
</span><span>Population are groups of living things that live together in a particular area. They are capable of interbreeding.
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Answer: Refractory period of the cardiac action potential
Explanation:
Unlike the skeletal muscle which can be reactivated before it reaches a contraction, cardiac muscle must wait before it is almost completely relaxed to be activated again (because of its long refractory period), so one cannot make an increase in strength of contraction with a high frequency of stimulations.
