The passage tells us that Telomerase (T) is only produced in cells that are actively dividing. Because of this, T is "generally absent" in adults.

However, there are two exceptions. T is present in adults':

(1) Bone marrow, which is continually dividing, and
(2) Cancer, in which cells are rapidly dividing.

So, bone marrow and cancer are exceptions to the rule that T is generally absent in adults. The reason why T is present in these particular cells is because they are dividing.

Which answer choice is most strongly supported by this information?


There is nothing in the passage to tell us telomerase is the only enzyme that is present in cancerous cells but absent from other cells. The passage only talks about telomerase but that doesn't mean other enzymes can't follow the same pattern.

For this reason, (A) is out.


You're right that "rapidly" and "actively" are not necessarily similar. This gives us a reason to eliminate (B): the passage tells us that telomerase is produced only in cells that are actively dividing. We're not worried about the speed of the division -- the passage implies that the cells could be dividing rapidly or they could be dividing slowly. As long as they're dividing, they will still produce telomerase.

This gives us the justification to eliminate (B).


From the passage, we know that telomerase will generally be absent from body tissues of adults. One of the exceptions to this rule is cancer cells. So, you would expect to find telomerase in an area where a person has cancer.

However, the other exception to this rule is bone marrow. The passage tells us bone marrow cells are "continually" dividing and are producing telomerase. Since these cells are always producing telomerase in their normal function, the fact we find telomerase in bone marrow is no indication of bone marrow cancer.

(C) is looking good, let's hold onto it for now.


The only information the passage gives us about cancer is that cancer cells produce telomerase. There is no information in the passage about the speed at which various cancers develop.

We can rule (D) out. Let's take a look at (E):

We're told that the two adult body tissues that produce telomerase are bone marrow cells and cancer cells, but we're not given any information about which of these types of cells produces telomerase more quickly.

From the information in the passage, we can't tell whether the level of telomerase production is always higher in cancerous cells than in noncancerous cells. It might be higher in bone marrow cells, we can't tell.

In addition, we have no idea about the level of telomerase production in children's tissues, whether cancerous or noncancerous.

This means we can eliminate (E), leaving us with (C) as our answer.

I hope that helps!