Digestive enzymes break down these complex molecules into smaller molecules the body can use. what would happen if digestive enzymes were not present?

All the food go to the waste which leads to poor health and physique.

If digestive enzymes were not present in the body, the food will not broken down into smaller molecules and no energy can be extracted from it which leads to poor health condition. Lack of digestive enzymes leads to poor digestion as well as malnutrition. It causes a disorder known as exocrine pancreatic insufficiency (EPI) in which pancreas doesn't make enough digestive enzymes so all the food go to the waste and leads to stunted growth.

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c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.