Answer: -inherited genes and environment
Inherited genes are the genes which an organism acquires from his parent. These genes are responsible for constructing genetic make up of the organisms. These genes are expressed in order to develop observable characteristics in organism also, called as phenotypic characteristics for example how an organism looks, behaves and reacts to external stimuli are all phenotypic characteristics. Environmental factors induces genetic and phenotypic changes in an individual to add up more traits which are beneficial to survive in changing environmental conditions for example maintenance of homeostasis in cold weather conditions, genetic traits will develop in order to compensate for loss of heat.