You are presented with the question "what do mammals use for heat?" and the following answer choices: 
- thermogenesis
 - Animal fur
 - feet
 - Chemical energy
 - fur and fat
 - layers of fat
 - convection
 - ice

Now knowing that mammals can also generate little bursts of heat by shivering and heat production is increased by shivering and non-shivering thermogenesis , choose the best answer.


 

 thermogenesis        