Answer:
The correct answer will be option A.
Explanation:
The electrical impulses are generated in the sino-atrial node or SA node, a mass of cells which generates impulse in the upper atrium.
This electrical impulse transmits from the sino-atrial node to the atrio-ventricular node in the lower portion of the upper atrium through the internodal pathway- the pathway composed of atrial cells.
Once the impulse reaches the AV node, it is transferred to the ventricular portion of the heart through Bundle of His presence in the ventricular septum. This bundle of his divides into left and right ventricles through bundle branches and stimulates both the ventricles.
Thus, option-A is the correct answer.
Answer:
Nonrenewable energy resources, like coal, nuclear, oil, and natural gas, are available in limited supplies. This is usually due to the long time it takes for them to be replenished. Renewable resources are replenished naturally and over relatively short periods of time.
Explanation:
The aquifer must be permeable and porous to allow the water to flow through.
B) the selection for different shaped beaks that best suit different niches
Answer:
Explanation:
Economics our environment are connected in an ongoing cycle we have created. Economics have a special influence on the environment because of the way we have set up our social system. There are many good affects of this cycle, such as people reserving land for endangered species. However, there are also bad affects, such as people monopolizing land just for themselves.