Plant produces glucose in the chloroplast through the process of photosynthesis. Calvin cycle is basically the biological process through which glucose is produced. The steps involved are as follows:
1. Absorbed CO2 is added to RuBP and 6C sugar is formed.
2. Breaking of 6C sugar into two 3-phosphoglycerate molecules
3. ATP gives phosphate group to form 3-phosphoglycerate which is later on converted into 1,3-biphosphoglycerate.
4. Electons are required by 1,3-biphosphoglycerate to an aldehyde called glyceraldehyde-3-phosphate or G3P and these electrons are donated by NADPH
5. Enzyme aldolase uses two molecules of G3P to produce 6 C sugar called fructose-1,6-biphosphate which is further converted to fructose-6-phosphate
6. Enzyme isomerase converts fructose-6-phosphate to glucose-1-phosphate
Plants get their energy from the Sun. animals would then eat the plants and get energy from the plants.
Any characteristic, whether a physical trait, a behaviour, a physiological adaptation etc can make an organism more or less likely to survive in a particular environment.
A dark colour could help a rabbit survive if it lives in a dark forest, because predators can't see it so well, but it would be less likely to survive in the arctic, where the environment is all white and it would show up.
In terms of the characteristics, think about: does it help the organism get food? Does it help protect the organism from predators? If it does, that organism is more likely to survive, and pass the characteristic on to it's offspring. If a bacterium has a characteristic of not being killed by antibiotics, this will help it to survive and breed.
