Question

what is the name given to organisms that produce their own food?
a autotrophs
b heterotrophs
c phototrophs
which of these is the ultimate source of energy for all organisms on earth?
a autotrophs
b decomposers
c the sun
heterotrophs obtain chemical energy from _.
a consuming other organisms
b photosynthesis
c decomposition

Explanation:

1. Organisms producing their own food are autotrophs. Heterotrophs rely on others, phototrophs use light (a subset of autotrophs).
2. The Sun is the ultimate energy source: autotrophs capture sunlight, which flows to other organisms.
3. Heterotrophs get energy by consuming other organisms; photosynthesis is for autotrophs, decomposition for decomposers.

Answer:

1. A. autotrophs
2. C. the Sun
3. A. consuming other organisms