What are his observations? We can’t answer this without knowing his observations if those are the conclusions. Please provide the rest of the information and I can answer.
The removal of the producers would cause the collapse of the entire food web. Primary consumers or herbivores, which feed on producers directly, would die off.
Sense of smell
Sense of smell is known to
be part of the chemosensory system or chemical senses. It also a warning
system that alert to danger signals such as fire, gas leakage or spoiled food.
Thus, the sense of smell comes from the specialized sensory cells known as
olfactory sensory neurons.
Carnivores also rely on plants because the herbivores are their source of food, and the plants feed the herbivores.