The “pacemaker” of the heart starts an electrical impulse in the right atrium to cause the atria to contract. what is the “pacemaker” of the heart? the sa node the av node the bundle of his the purkinje fibers

Hello!! The answer would be A - The SA node. It is known as the "pacemaker" because it initiates the heart's rhythmic contractions. I hope I helped!! Have a great day. :)

The correct answer is "the SA node".

Explanation:

The heart beat is triggered by electrical impulses and among them, the sinoatrial node (SA node) is the one that receives the name of the “pacemaker” of the heart. The impulse of the SA node begins with a bundle in the right atrium, which spreads through the walls of the atria and causes a contraction. The SA node is the principal factor that affects the rate and rhythm of the heartbeat.

there are mainly three domains in biological classification namely; archaea, bacteria, and eukarya.

archaea includes all the prokaryotic cells which are characterized by their lipid membranes. they have branched hydrocarbon which is attached to glycerol through an ether linkage.

bacteria includes all the prokaryotic cells, the cell membrane of which are made up of the unbranched fatty acid chain. in addition, they are attached to glycerol through an ester bond.

eukarya includes all the eukaryotic cells, that is, the cells contain a nucleus and other membrane-bound cell organelles.

they can be autotrophic as well as heterotrophic, unicellular as well as multicellular

they include kingdoms like protista, plantae, animalia, fungi et cetera.

read more on -

explanation: