Final answer:
All animal cells require oxygen for cellular respiration, where oxygen is used to produce energy from glucose. Specialized respiratory systems have evolved in larger animals to efficiently transport oxygen throughout the body. Oxygen is vital for energy production and carbon dioxide is a waste product that must be removed.
Step-by-step explanation:
The statement that all animal cells need oxygen is true. Each cell in the body requires oxygen because it is a critical component of cellular respiration, a process in which cells produce energy. Cellular respiration can be summarized by the equation:
Oxygen + glucose → Carbon dioxide + water + energy
In this process, oxygen is used to break down glucose, releasing energy that cells use to perform various functions. Therefore, without oxygen, cells would not be able to produce energy efficiently and could not sustain life.
Larger animals have evolved specialized respiratory systems to ensure that oxygen reaches all cells. The complexity of these systems, such as lungs and gills, coupled with circulatory systems, are necessary to transport oxygen to and remove carbon dioxide from cells.
The body requires oxygen to generate energy and gives off carbon dioxide as a waste product because, during the energy production process, carbon dioxide is produced and must be expelled to maintain proper functioning.
As for the questions related to the respiratory system, blood returns back to the heart after oxygen has been delivered to cells and carbon dioxide has been collected for expulsion. This cyclical process is essential for maintaining homeostasis within the body.