D hoped this helped you a lot! :s
We can tell from their structure that fatty acids are a good source of energy because of their large number of carbon-hydrogen and carbon-carbon bonds that they contain. Most fatty acids have straight chain compounds with an even number of carbon.
Answer:
Biofuels are renewable fuels that are produced from biomass, organisms that were formed and stopped living a short time ago. The energy in the biofuels is called bioenergy. The major constituents of biomass are cellulose, lignin, starch and sugar, but many plants also contain other organic compounds that are beneficial for energy recovery from the material due to their physical structure and chemical composition. The difference between biofuels and fossil fuels is that fossil fuels take millions of years for new formation while new biomass for biofuels is constantly being formed. This means that biofuels can usually be considered carbon neutral as the carbon dioxide emitted during combustion is constantly bound to new biomass in a closed cycle.
Internal stimuli causes a response within an organisms body. Among the choices given only one of them is an effect because of an internal stimuli, which is a child having a fever. The internal stimuli that cause such a response could be a bacteria or virus.
If you consider the other like the chipmunk running and owl sleeping in a tree, those two are responses to predators, which are outside the body. A dog panting and snake moving to a sunny rock is a response to the temperature of their environment, which is outside the body as well.
