- Electrical signals in the brain travel through nerves to muscles - Two types of proteins exist in filaments in the muscles - The filaments move when the brain instructs them to - The motion of the filaments cause the muscle to shorten and contract What might be the last step of the process?
Ans: Opposing pairs of muscles exist in order to provide the necessary range of motion.

- Fluid - Waste enters the kidneys - A processing moment in the kidneys let waste and fluid pass - Prevents larger molecules to pass - Fluid goes back to the bloodstream - Bad waste is removed What might be the last step of the process?
Ans: The final product is turned into urine.

- Blood enters the kidney - The blood travels into the neophrons - Waste is expelled via the neophrons - The waste goes to the bladder in the form of urine What might be the last step of the process?
Ans: The clean blood exits the kidneys.

- Carbon dioxide from the air passes through small pores (holes) in the leaves - These pores are called stomata - Water is absorbed by the roots - It passes through vessels in the stem on its way to the leaves What might be the last step of the process?
Ans: Sunlight is absorbed by a green chemical in the leaves.