NCERT In Text

What are outside raw materials used for by an organism?

An organism uses outside raw materials mostly in the form of food and oxygen. The raw materials required by an organism can be quite varied depending on the complexity of the organism and its environment.

Related Questions Life Processes

Enzymes break-down the various complex components of food into simple and soluble components so that they can be absorbed easily.

Aerobic respiration Anaerobic respiration
It occurs in the presence of O2. It occurs in the absence of O2.
It involves the exchange of gases between the organism and the outside environment. Exchange of gases is absent.
It occurs in cytoplasm and mitochondria. It occurs only in cytoplasm.
It always releases CO2 and H2O. End products vary.

Anaerobic respiration occurs in the roots of some waterlogged plants, some parasitic worms, animal muscles, and some micro-organisms such as yeasts.

If plant is releasing carbon dioxide and taking in oxygen during the day, it means that respiration is happening in plant. But it does not mean that photosynthesis is not happening. Carbon dioxide released after respiration comes out of stomata. For photosynthesis, the plant takes in carbon dioxide from atmosphere. In other words, plant does not depend on respiration for carbon dioxide for photosynthesis.

Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organism can also have movements, which are not visible to the naked eye. Therefore, the presence of life processes is a fundamental criterion that can be used to decide whether something is alive or not.

All of them are parasites. They live on or inside the body of another organism to get food. They always harm their hosts.