2006-10-05 11:54:30 · 5 answers · asked by toshihironoguchi123 2 in Science & Mathematics ➔ Biology
They have no "brain", and most don't even have anything resembling a "nervous" system. Their behavior is determined by chemical actions within their bodies.
2006-10-05 11:58:25 · answer #1 · answered by MrZ 6 · 0⤊ 1⤋
They have a nucleus. Their behavior is all "written" in their nucleus. It tells the protist how to live and what to do. It tells what each part is for and how to get food, etc. That is why the behavior is instinct or already their, unlike us our brain make us think.
2006-10-05 12:00:30 · answer #2 · answered by t_nguyen62791 3 · 0⤊ 0⤋
They have a brain, but it isn't a brain that any Human or animal we know of. Any thing that moves has to have a brain. But not a brain like anything else.
2006-10-05 12:04:11 · answer #3 · answered by John T. 2 · 0⤊ 0⤋
They are controlled by responses to environmental stimuli including chemicals, light and heat. In similar manner, white blood cells which don't have a brain can attack and engulf foreign invaders.
2006-10-05 13:00:25 · answer #4 · answered by PaulCyp 7 · 0⤊ 0⤋
They are controlled by chemistry alone; RNAs, proteins and DNA acting in concert.
2006-10-05 12:16:45 · answer #5 · answered by Pseudo Obscure 6 · 0⤊ 0⤋