Question

Diffusion is insufficient to meet_____________requirement of multicellular organisms.
(a) Carbon dioxide
(b) Oxygen
(c) Nitrogen
(d) Sulphur

Answer 1

Hint: This gas is very much essential for the process of aerobic respiration because it is used up by the body for the breakdown of food molecules.

Complete answer:
Diffusion is a slow process in which particles of liquids, gases, or solids mix up with each other as a result of their spontaneous movement. The presence of multiple layers of cells in multicellular organisms shows the low ratio of surface area to volume, this results in slow diffusion. If the only diffusion would have been the source of oxygen supply then only the outer layer of the body would get oxygen and the inner layers would be lacking oxygen because all the cells are not on the surface in multicellular organisms. This will result in the death of the organism.

Additional information:
- Carbon dioxide plays an important role in various processes in plant and animal, such as photosynthesis and respiration.
- Carbon dioxide and water are converted into glucose and oxygen by the process of photosynthesis.
- Nitrogen is very much important for life. It is the main constituents Of amino acids, proteins and even DNA.
- Sulphur is also important for life. It is the minor constituents of fats, body fluids, and skeletal minerals. Sulphur is a key component in most proteins since it remains present in the amino acids methionine and cysteine.

So, the correct answer is oxygen.

Note:
1. Many simple organisms, such as fishes, do not have specialized respiratory structures and instead obtain oxygen by diffusion through their body surfaces.
2. Respiration is generally of three types: internal respiration, external respiration and cellular respiration.
3. External respiration means the process of breathing that involves inhalation and exhalation of gases.
4. Internal respiration means the process of exchange of gases between blood and the body cells.
5.cellular respiration is the process that involves the final breakdown of food into energy in the form of ATP. It is of two types: aerobic and anaerobic respiration.
6. Aerobic respiration occurs in the presence of oxygen whereas anaerobic respiration occurs in the absence of oxygen.