SCIENCE
CIRCULATORY SYSTEM
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Body volume is too large
|
|
|
Total surface area per volume ratio becomes too large
|
|
|
Total surface area per volume ratio becomes too small
|
|
|
Total surface area is insufficient
|
Detailed explanation-1: -Large, multicellular organisms need ways to ensure that all cells can get the substances that they need to survive. These may include: mechanisms to increase surface areas for diffusion, such as additional absorption areas or adaptations of shape. transport systems that keep distances for diffusion short.
Detailed explanation-2: -Smaller single-celled organisms have a high surface area to volume ratio, which allows them to rely on oxygen and material diffusing into the cell (and wastes diffusing out) in order to survive. The higher the surface area to volume ratio they have, the more effective this process can be.
Detailed explanation-3: -Large multicellular organisms therefore cannot rely on diffusion alone to supply their cells with substances such as food and oxygen and to remove waste products. Large multicellular organisms require specialised transport systems.
Detailed explanation-4: -They have specialised cells and tissues for performing various necessary functions of the body such as intake of food and oxygen. Unlike unicellular organisms, multicellular cells are not in direct contact with the outside environment. Therefore, diffusion cannot meet their oxygen requirements.