Question

Can humans use photosynthesis?

Answer 1

Hint: Human beings are heterotrophic animals and consumers. They obtain food from plants and animals belonging to lower trophic levels. Photosynthesis takes place with the help of chloroplast which helps in the production of food and oxygen.

Complete answer:
Photosynthesis takes place with the help of light energy in plants and algae. The chloroplast is the main photosynthetic organ that consists of chlorophyll pigment inside the green leaves of a plant which is helpful in photosynthesis. Humans do not have chlorophyll pigment nor they have chloroplast therefore they aren't able to perform photosynthesis. But they use photosynthetic products like food and oxygen which is important for their survival. Therefore humans not directly but indirectly use photosynthesis in the form of their products.

Additional information:
Photosynthesis is a very important process on earth that helps in the survival of many living organisms. Despite food and oxygen photosynthesis also help in making useful plant products like fodder, timber, firewood, fibres, resins, rubber, drug, etc. The photosynthesis process requires carbon dioxide for making carbohydrates which helps to decrease the concentration of carbon dioxide in the atmosphere produced by organic fuel burning and living organisms respiration. The oxygen obtained from photosynthesis helps in the utilisation and breakdown of the respiratory substrate. It also makes up the ozone in the stratosphere which filters out harmful radiations and prevents it from reaching the earth.

Note:
In the atmosphere, $0.03\mathrm{\%}$ of carbon dioxide is present by volume, which represents about 2200 billion tonnes which is sufficient to support photosynthesis for a few hundred years. 70 billion tonnes of carbon dioxide fix annually for both terrestrial and aquatic photosynthetic organisms.