Answer:
Genetic variation
Explanation:
It could lead to natural selection, but natural selection isn't the cause. Many years down the road you could see a particular variation having a higher population, which is the result of natural selection/survival of the fittest via better camouflaging from predators.
The beaker's wide mouth makes it easier to add and remove test tubes without spilling
Instructions for each specific function
Answer:
The first one is A: Digestive system
The second is C: Glucose
The third is C: Insulin
Explanation:
:)