Most natural food chains are only four or five links long, rarely more. the number of trophic levels is limited because

Which macromolecules are polymers made of nucleotides (a) fatty acids (b) nucleic acids (c) carboxylic acids (d) amino acides

Food provides molecules that serve as fuel and building material for all organisms. plants undergo photosynthesis and make their own food. other organisms, like us and the horse seen above, are consumers and eat food. how do all organisms use food as fuel? be sure to include the name of the process in your answer. me.

What does it mean for a cell membrane to be selectively permable