explanation: there is no water in the food web. the snake is a carnivore and only eats meat (meaning it doesn’t get its energy from grass), the hawk only eats the mice and rabbits. the only choice left would be the grasshopper. (plus it shows the arrow coming from the grass pointing to the grasshopper, implying that the grasshopper gets its energy from the grass).
The main organelle involved in respiration is the mitochondria. It's known as the powerhouse of the cell due to the fact that 32 ATP are created from this organelle.
