Which of the following statements about mercury is false?
a. methyl mercury compounds are unusual in that they cannot cross the body's blood-brain barrier.
b. significant amounts of mercury are released into the environment during the smelting of other metals.
c. human exposure to mercury is primarily by eating marine animals containing high levels of mercury.
d. methyl mercury compounds are more toxic forms of mercury that readily enter the food web.
e. methyl mercury compounds persist in the environment for a long time.

Option (A).

Explanation:

The element mercury can persist in the environment and proves to be harmful for the living organism. The mercury persist in the lower organism and transfer to the higher organism by the process of biological magnification.

The compounds of methyl mercury are not harmful. The methyl mercury compound cannot cross the blood-brain barrier and does not affect the individual.

Thus, the correct answer is option (A).

one comes through sex and the other does not lul im not

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]