In vertebrate animals, the same organ in different species often have different structures. for example, the heart of a fish has two chambers while the heart of a mammal has four chambers. what is an explanation for these differences in organ structure? a) reproductive differences b) differences in the size of the animals c) mutation of the genes of the organisms d) adaptation of organisms to their environments

the correct answer is option b

behavioral response need communication and thus co-ordination at several levels such as interaction among cells, organ system and the entire organism.

behavioral response produces both internal and environmental stimulus.

primary succession occurs in essentially lifeless areas regions in which the soil is incapable of sustaining life as a result of such factors as lava flows, newly formed sand dunes, or rocks left from a retreating glacier. secondary succession occurs