In the food chain grass ,grasshopper, snake, hawk , which organisms are the heterotrophs?

The grasshopper, snake, and hawk are all heterotrophs. This is because they CANNOT make their own food, but grass can(photosynthesis).

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .

unicellular organisms, like bacteria, are able to perform all life functions within one single cell. multicellular organisms need many different types of cells to carry out the same life processes. each of these special types of cells has a different structure that it perform a specific function.