The answer is atrial depolarization. The P wave of a normal electrocardiogram specifies atrial depolarization. In addition, depolarization happens in the four compartments of the heart which is both atria first and in both ventricles. The sinoatrial or as called as SA node on the wall of the right atrium starts depolarization in the right and left atria that can cause the contraction in which it is symbolized by the P wave on an electrocardiogram.
The type of muscle tissue that does not contain gap junction is SKELETAL MUSCLES.
Gap junction function by allowing the free diffusion of ions and small molecules between two cells. The number of gap junction between any two cells will vary and will depend on the type of cell they are.
Answer:
The correct answer is - speciation is sympatric.
Explanation:
Sympatric speciation is a process of speciation that takes place when there is reproductive isolation between two populations of a species without any geographical separation.
This speciation takes place in the population with come ancestors as given in the question both pods of dolphins lose their ability to interbreed due to the sympatric speciation without any geographical separation.
Thus, the correct answer is - speciation is sympatric.