<span>a. Fish have a single central heart; earthworms have several hearts.
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Multi cellular organisms are made up of billions of cells each specialized to a unique role and these cells are organized into structural and functional units such as tissues and organs.
For each cell and organ to function optimally, it requires oxygen and nutrients and needs carbon dioxide and metabolic waste taken away in a continuous, never ending process.
<span>A mechanism is needed to accomplish the important function of transporting the relevant materials to and from the cell. The circulatory system fits this bill splendidly. It is a specialized organ system which allows blood and lymph to flow through the entire body carrying nutrients such as glucose, amino acids and electrolytes as well as oxygen to each cell, at the same time carting away carbon dioxide and all sorts of metabolic waste over to excretory organs to be expelled from the body.
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Answer;
-Structural isomers.
Explanation;
-Isomers are molecules that have the same molecular formula, but have a different arrangement of the atoms in space.
-Structural Isomers are molecules which have the same molecular formula but have different connectivities. That is; the molecules have the same molecular formula, but their atoms have different arrangements or bonds.
-For example, butane and isobutane are structural isomers, also called chain isomers. In chain isomers, the carbon atoms are connected in different orders. Isobutane and butane have a molecular formula of C4H10.
Answer:
In simplest terms, water makes up about 71% of the Earth's surface, while the other 29% consists of continents and islands.
Explanation:
The period of time that begins with the contraction of the atria and ends with ventricular relaxation is known as the Cardiac cycle.
<h3>What is a cardiac cycle?</h3>
The cardiac cycle describes a whole heartbeat from its onset to the beginning of the following pulse. It consists of the diastole, systole, and the interval in between. Heart rate, which is naturally expressed as beats per minute, serves as an example of how a cardiac cycle occurs.
<h3>Cardiac Cycle Physiology</h3>
The left and right halves of the human heart's four chambers make up the body. The right and left ventricles are located in the lower two chambers, while the left and right atria are located in the two top chambers. Pumping deoxygenated blood to the lungs through the pulmonary arteries and the pulmonary trunk is the right ventricle's main job. While the left ventricle is in charge of pushing freshly oxygenated blood to the body through the aorta.
Learn more about deoxygenated blood here:-
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