A by-product of photosynthesis is oxygen gas which is required for respiration by plants and animals.
(A by-product of photosynthesis; is; oxygen gas which is required for respiration by plants and animals) (oxygen gas; is required; for respiration; by plants and animals)
A by-product of photosynthesis oxygen gas
is is required
oxygen gas which is required for respiration by plants and animals
for respiration by plants and animals