why can't animals undergo photosynthesis?

Answer 1

Photosynthesis is the process by which plants convert sunlight to food and energy. Animals gain food and energy from eating other things and have no need for photosynthesis. I guess you could say that they "can't" because there is no need to so they didn't develop that ability.

Answer 2

Because they lack the photosynthetic pigments such as chlororophyll which would enable them to do so. Chlorophyll and other pigments such as the carotenoids capture the energy from sunlight and use it to cause a chemical reaction combining carbon dioxide and water to make a sugar (glucose). In this way plants make their own food, while animals eat other organisms to get their food. This means that animals have by-passed photosynthesis by letting the plants make the food and then the animals eat the plants (either directly as in herbivores or indirectly as in carnivores which eat the herbivores).

Interestlingly, it would seem that the chemical structure of Chlorophyll was so useful that animals have put it to another use - the structure of Haemoglobin (used to transport oxygen in the blood) is incredibly similar to that of Chlorophyll; both being what are know as porphyrin rings.

Answer 3

Burning fat and protein is MUCH less efficient than photosynthesis. Photosynthesis is one of the most efficient energy models known in the world. The efficiency isn't an issue, it's the speed. The reason we animals can't is because we don't have the pigments and cellular content to do so.

Answer 4

Animals cannot undergo photosynthesis because they breathe oxygen(o2), not carbon dioxide(co2). For photosynthesis to occur, the organism must be intaking carbon dioxide, its kind of like how animals grow, they need oxygen, vice versa, a plant needs co2 to undergo its growth stage, known as photosynthesis

Answer 5

Plants have special organelles inside of their cells called "chloroplasts" which convert carbon dioxide and light energy into a sugar called glucose. These chloroplasts allow plants to photosynthesize, and also give them their green color.

Animals have no chloroplasts, and thus they cannot photosynthesize. Even if they could, they wouldn't be able to get enough energy doing it to live, because animals expend more energy that they can take in, given the surface area of their skin and the intensity of sunlight.

Answer 6

God made animals mobile and didn't provide with chlorophyll. Like plants, They can't stand under the Sun and cook!!!!

Answer 7

I reckon the main reason being that animals do not have any chlorophyll content in their composition.

Answer 8

because animals dont have the green pigment called chlorophyll

Answer 9

They don't have chlorophyll, which is required for the process, in their skin or on their bodies

Answer 10

Because it wouldn't fulfill their energy needs. Burning fat cells and/or protein is more energy efficient and does not rely on the sun.