Two brothers, Tom, aged 26, and Paul, aged 16 were into sports. Tom started weight-lifting to gain more muscle mass. Three years later he was 20-25 lbs. heavier. Paul started track and field, he liked running. Which brother had thinner bones after three years? Hint: A baby is born with zones of cartilage in its bones that allow growth of the bones. These areas, called growth plates , allow the bones to grow longer as the child grows. By the time the child reaches an age of about 18 to 25 years, all of the cartilage in the growth plate has been replaced by bone. This stops the bone from growing any longer. Even though bones stop growing in length in early adulthood, they can continue to increase in thickness throughout life. This thickening occurs in response to strain from increased muscle activity and from weight-lifting exercises.
Ans: Paul

Mike is studying for his biology exam. He found that all body cells are not equal in size - some are large and some are small. He labeled the large cells as class A cells. Then he labeled the small cells as class B cells. He is now prepared to find the differences between them. Which cells would have more folds on its membrane, class A or class B? Hint: As a cell grows, its volume increases more quickly than its surface area. If a cell was to get very large, the small surface area would not allow enough nutrients to enter the cell quickly enough for the cell's needs. This idea is explained in Figure below . However, large cells have a way of dealing with some size challenges. Big cells, such as some white blood cells, often grow more nuclei so that they can supply enough proteins and RNA for the cell's requirements. Large, metabolically active cells often have lots of cell protrusions, resulting in many folds throughout the membrane. These folds increase the surface area available for transport of materials into or out of the cell. Such cell types are found lining your small intestine, where they absorb nutrients from your food through protrusions called microvilli .
Ans: class A

Kathy and Jacob are two coworkers out having a drink at a bar after a day at the office. They both wear glasses and Kathy comments that she hates that she is so farsighted and wishes there was a surgery to fix it. Jacob says that he finds it amusing she is farsighted because he himself is nearsighted. They both laugh at the opposite nature of their eye condition, and then both look at the menu on the other side of the room to decide what drinks to order next. Which person's eyes naturally don't focus images behind the retina? Hint: Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure below ). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it.
Ans: Jacob

Robert, a baker, has just baked a large batch of cupcakes for his store. He won't be able to sell all of his cupcakes within the next week, so he has decided to store a portion of them in the freezer to preserve them for later. He is trying to decide if he should store the cupcakes at 0 F or at 10 F in the freezer. Which temperature will result in faster growth of micro-organisms on the cupcakes? Hint: Freezing is a common method of food preservation that slows both food decay and the growth of micro-organisms. Besides the effect of lower temperatures on reaction rates, freezing makes water less available for bacterial growth.
Ans: 10 F