Which of the following phenomena best explains why pregnant women should limit their intake of mecury-containing fish such as tuna?
A Bioavailability
B Biomagnification
C Bioconcentration
D Biolimitation
The correct answer and explanation is:
The correct answer is B. Biomagnification.
Biomagnification refers to the process by which the concentration of certain substances, like mercury, increases as it moves up the food chain. Mercury is a heavy metal that can accumulate in the environment, especially in water bodies. When smaller organisms, such as plankton or small fish, absorb mercury from the water, it remains in their system. As larger fish or predators eat these smaller organisms, the mercury concentration in their bodies increases, often reaching harmful levels. This effect becomes more pronounced as the organisms higher in the food chain consume larger amounts of contaminated prey.
Pregnant women are particularly at risk from mercury exposure due to its toxic effects on fetal development. Mercury can cross the placenta and adversely affect the developing nervous system of the fetus. This can lead to developmental delays, cognitive impairment, and other neurological issues in the child. Fish such as tuna, which are high on the food chain, tend to accumulate significant amounts of mercury, making them a major concern for pregnant women who consume them regularly.
By limiting their intake of mercury-containing fish, pregnant women can reduce the potential exposure to this harmful substance. While biomagnification is the primary reason for mercury accumulation in fish, other related phenomena such as bioaccumulation (which refers to the buildup of substances in an individual organism) and bioconcentration (the concentration of substances in aquatic organisms from water) also play a role. However, biomagnification specifically explains the increased mercury levels in the food chain, making it the most appropriate answer.