Answer:
in the wall of the right atrium of the heart.
Explanation:
The sinoatrial node (SA), consisting of spindle-shaped cells, initiates the electrical activity of the heart. From its location in the right atrium in proximity to the superior vena cava, the electrical activity spreads to the atria, whose cells are larger than those of the SA.
Answer:
The correct answer is - option D.
Explanation:
In algae or any other photosynthetic organism, there is the internalization of carbon dioxide gas in the reaction with water in the presence of sunlight to produce sugar molecules and oxygen gas in the atmosphere. So, photosynthesis is the process that releases or produces oxygen gas.
In cellular respiration (aerobic) the product of photosynthesis, glucose molecules, and oxygen react to produce the energy and releases carbon dioxide and water as byproducts.
So, the correct answer is - option D.
