Question

1. if a person is breathing normally, which of the following could prevent him from using his body to exercise normally?

not getting enough sunlight, because cells need sunlight to function
not getting enough sleep, because the body only makes energy for exercise while asleep
not eating enough food, because cells need molecules from both food and air to work
nothing, because he would be able to exercise normally as long as his cells are getting molecules from the air

1. some types of syrup are almost entirely made of glucose molecules. if a person ate some syrup like this, what would happen to her ability to exercise?

it would be harder for her to exercise because her digestive system would need to use more enzymes to combine the glucose molecules together.
it would be easier for her to exercise because glucose moves through the circulatory system faster than other food molecules usually do.
nothing would happen to her ability to exercise, but her respiratory system would not work as hard, since glucose has more energy than oxygen molecules.
nothing would happen to her ability to exercise, but her digestive system would not work as hard, since glucose is already small enough to get to her cells.

Explanation:

Question 8

• First option: Cells don't need sunlight to function (except plants in photosynthesis), so this is incorrect.
• Second option: The body makes energy (ATP) through cellular respiration which can occur during wakefulness too, not only during sleep, so this is wrong.
• Third option: Cells need nutrients (from food) and oxygen (from air) for cellular respiration to produce energy for exercise. Not eating enough food would limit the molecules (like glucose) needed for energy production, so this is correct.
• Fourth option: Cells need both food (for glucose etc.) and air (for oxygen) to produce energy. Just getting molecules from air isn't enough, so this is wrong.

• First option: Glucose is a monosaccharide, so the digestive system doesn't need to combine glucose molecules together (that's for polysaccharides like starch). So this is incorrect.
• Second option: Glucose is a simple sugar and is absorbed quickly into the bloodstream, so it can be transported to cells faster to be used for energy (ATP production) during exercise, making exercise easier. This is correct.
• Third option: Glucose doesn't have more energy than oxygen molecules, and the respiratory system's work is related to gas exchange (oxygen intake, CO₂ release) for cellular respiration, not directly related to glucose's energy content in this way. So this is wrong.
• Fourth option: While glucose is small enough to get to cells, it does affect exercise ability as it provides a quick energy source, so saying nothing happens to exercise ability is wrong. Also, the digestive system still has some work (absorption etc.), but the main error is about exercise ability.

Answer:

C. not eating enough food, because cells need molecules from both food and air to work

Question 9