A plant is placed in sunlight. The plant has one leaf marked A and one leaf marked B. Leaf A is covered with aluminum foil but leaf B is not. After five days, both leaves are removed from the plant. The amount of starch present in leaf A is compared to the amount of starch in leaf B. Which hypothesis is being tested in this investigation?

Explanation:

I don't understand bioligy

Weakening of digestive smooth muscle with age can cause constipation.

Explanation:

Smooth muscles in the digestive system have the role to move food down the tract via radially symmetrical contractions (peristalsis). With age, the function of smooth muscles reduces, causing the food to move more slowly through the alimentary canal (digestive tract). As a consequence, water gets absorbed from food waste, which can cause constipation.