Answer:
This question lacks options, the options are:
A) Saliva converting the starch molecules in crackers into simple sugars
B) Digestive enzymes breaking down proteins into smaller fragments
C) bacteria converting lactose into simple sugars in the intestines
D) teeth grinding an almond into smaller pieces in the mouth
The answer is D
Explanation:
A physical change is a change that occurs to a substance without altering its chemical composition. A physical change involved a change in the substance's shape, texture, color, state etc. but not the chemical content of such substances.
In this question involving the processes that occur in digestion, a typical example of physical change is "teeth grinding an almond into smaller pieces in the mouth" because the teeth only changes the shape and texture of the almond. It does not affect the chemical composition of the almond fruit. This is also called mechanical digestion.
Note that, other options involving digestive enzymes breakdown are chemical changes because the enzymes breakdown the chemical components of each substance.
