The right answer is The first image (the left one).
An atrium is an upper cavity of the heart, delimited by a thin wall, receiving blood from the bloodstream. There are two in the human heart, they allow the passage of blood from the veins (cellars and lungs) to the ventricles (right and left).
In its upper part (near the entrance of the superior vena cava) is located the sinus node, microscopic structure from which the electrical impulse which ensures the contraction of the heart (especially atrium) ...
The depolarization of the action potential is conducted step by step in the cells of the right and left atria, accompanied by a contraction of the muscle fibers.
The mechanism for evolution is natural selection
The offspring is unique and is not like its parent plant.
Answer:
The coconut palm seeds are prevented from dispersing to higher ground due to the limitations of gravity, which pull the coconuts down any slope steep enough when falling.