Biomagnification and Mercury Exposure

Mr. Smeeds introduces the topic of biomagnification, explaining the difference between bioaccumulation and biomagnification. Bioaccumulation refers to the buildup of pollutants in an organism over time, while biomagnification describes the increasing concentration of these pollutants at higher trophic levels in a food chain. The video uses examples like DDT and mercury to illustrate these concepts and their ecological impacts. The session concludes with a task to design a testable hypothesis related to biomagnification.

What is the main objective of the video tutorial?

• To understand the process of photosynthesis

• To study the anatomy of marine animals

• To describe biomagnification and bioaccumulation and their effects on ecosystems

• To learn about the water cycle

What is bioaccumulation?

• The buildup of water-soluble pollutants in organisms

• The buildup of fat-soluble contaminants in the bodies of organisms over time

• The process of organisms excreting waste

• The accumulation of nutrients in the soil

Why do persistent organic pollutants (POPs) not easily exit the body?

• Because they are fat-soluble

• Because they are water-soluble

• Because they dissolve easily in water

• Because they are excreted as waste

How does biomagnification differ from bioaccumulation?

• Biomagnification occurs in individual organisms, while bioaccumulation occurs in food webs

• Bioaccumulation occurs in individual organisms, while biomagnification occurs in food webs

• Bioaccumulation involves the entire ecosystem, while biomagnification involves only plants

• Biomagnification involves water-soluble pollutants, while bioaccumulation involves fat-soluble pollutants

What is the 10% rule in the context of biomagnification?

• Organisms at higher trophic levels consume 10% more biomass

• Only 10% of energy is transferred to the next trophic level

• 10% of pollutants are excreted as waste

• 10% of organisms are affected by biomagnification

What was DDT primarily used for before it was phased out?

• As a fertilizer

• As a broad-spectrum insecticide

• As a water purifier

• As a food preservative

What effect did DDT have on the eggshells of birds like the bald eagle?

• It made the eggshells more colorful

• It had no effect on the eggshells

• It caused the eggshells to thin, leading to hatchling deaths

• It made the eggshells thicker

What is the primary human source of mercury release into the atmosphere?

• Agricultural runoff

• Deforestation

• Combustion of coal

• Plastic production

What form of mercury is highly toxic and produced by bacteria in aquatic ecosystems?

• Mercury chloride

• Elemental mercury

• Methylmercury

• Mercury oxide

How can humans be exposed to methylmercury?

• By using mercury thermometers

• By eating large predatory fish like tuna and salmon

• By drinking contaminated water

• By inhaling air near coal-fired power plants