Author Question: What is the origin of most childhood cancers? a. Placenta b. Environment c. Mesodermal germ ... (Read 30 times)

SAVANNAHHOOPER23 · **on:** Jun 25, 2018

What is the origin of most childhood cancers?

a. Placenta
b. Environment
c. Mesodermal germ layer
d. Neural tube

Question 2

The role of physical activity in the prevention of colon cancer is identified by which of the fol-lowing?

a. It increases fluid loss, leading to thirst and increased fluid intake, hydrating the co-lon.
b. It increases blood supply, thereby increas-ing oxygen to the colon.
c. It increases gut motility, thereby decreas-ing the time the bowel is exposed to mu-tagens.
d. It increases the secretion of hydrochloric acid, thereby killing mutants.

kiamars2010 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: C
Most childhood cancers originate from the mesodermal germ layer that gives rise to connective tissue, bone, cartilage, muscle, blood, blood vessels, the gonads, the kidney, and the lymphatic system. Most childhood cancers do not originate from the placenta or the environment. Neural tubes are generally not associated with cancer.

Answer to Question 2

ANS: C
Physical activity increases gut motility, thereby decreasing exposure to mutagens. Physical activ-ity does increase fluid loss and blood supply, but neither effect prevents mutagens. Physical ac-tivity does not increase hydrochloric acid.