Question

The human digestion system breaks down the bulk food we consume into components we can absorb. What would most likely happen over a long period of time if all humans relied on fruits and vegetables as their primarily food source?

Herbivores would quickly become meat eaters.

Human digestive tracts would eventually become shorter.

Human digestive tracts would eventually become longer.

Protein would no longer be needed in humans.

Answer 1

The answer will be human digestive tracts would eventually become longer (Third option).

Explanation: Humans are omnivores. If they relied on only fruits & vegetables as their primary food source, they will become herbivores. Herbivores can't quickly become carnivores (meat eaters). Herbivores also require protein in their diet. So, we can ignore first & last options. To absorb nutrients & having more time to digest plant materials, herbivores have longer digestive tract than humans. So, if human becomes herbivores, their digestive tracts would eventually become longer. Thus, third option is the correct answer.