Answer:
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.
Answer:
The main purpose of research is to inform action, to prove a theory, and contribute to developing knowledge in a field or study.
Explanation:
If your car is changing speed by accelerating or decelerating, or changing directions by turning or hitting a bump, your body can sense these accelerations. You might be pressed against the back of your seat while speeding up or against the car door as you turn for example. If you are cruising at a constant speed, with no changes in speed or direction, you wouldn't be able to feel it. You would need to use your other senses. You could see the scenery going by through the windows, with closer objects moving by more quickly than objects in the distance. You could also hear sounds like the wind rushing by and the hum of the tires rolling on the highway.
Answer:B. Sunlight provides energy to producers
Explanation: photoautotrophs (plants) produce energy from sunlight by photosynthesis. This is the only energy production based on an external source of energy. Plants, whether alive or dead, are consumed by heterotrophs - bacteria, fungi and animals. The nutrients and energy from dead heterotrophs (and some live ones) are recycled by both autotrophs and heterotrophs.