09 Bioaccumulation

Question 1

what are toxins?

Answer 1

Toxins are defined as substance that cause
damage to biological systems by chemical
means.

Question 2

how can toxins be produces

Answer 2

Toxins can also be produced by living
organisms, but the more harmful toxins are
produced by humans.

Question 3

what are examples of toxins in the avg household

Answer 3

◦ Drain Cleaner
◦ Gasoline
◦ Battery Acid

Question 4

what are biodegradable substances

Answer 4

Biodegradable substances are naturally broken down

in the environment.

Question 5

what are some examples of biodegradable substances?

Answer 5

eg sewage (feces and urine),
dead organisms.

Question 6

what are non-biodegradable substances

Answer 6

Non-biodegradable substances are broken down very
slowly or not broken down at all by natural
processes, once they enter the ecosystem they do
not leave.

Question 7

what are some examples of non-biodegradable substances?

Answer 7

plastics, pesticides

Question 8

some non-biodegradable substances are ______

Answer 8

toxins

Question 9

what is bioaccumulation?

Answer 9

Accumulation of a substance within an organism

at a single trophic level.

Question 10

_______ are absorbed by organisms through _______________ in regards to bioaccumulation

Answer 10

Pesticides and other poisonous substances are
absorbed by organisms through air, water, and
food.

Question 11

when does bioaccumulation occur

Answer 11

Bioaccumulation occurs when the toxic substance

is absorbed by the organism faster than it is lost.

Question 12

in bioaccumulation over time ________

Answer 12

the pollutant accumulates

Question 13

what is an example of bioaccumulation

Answer 13

Grass absorbing

pesticides over time.

Question 14

bioaccumulation regarding fish:

Answer 14

For example, mercury can bioaccumulate in
fish:
◦ Over time, since the fish absorb mercury faster than
they expel it, harmful levels of mercury in the fish
are reached:

Question 15

what does bioaccumulation damage

Answer 15

whole species and ecosystems

Question 16

each species plays a ______ role in an _______

Answer 16

role, ecosystem

Question 17

what are keystone species. What Is 1 example

Answer 17

species that
has a large impact on an
ecosystem. eg fish

Question 18

If the numbers of a species (like fish) decline due to

bioaccumulation, what happens

Answer 18

the species that it consumes (like
algae or shrimp) will thrive while the species that
consume it (like otters) will starve.

Question 19

what is biomagnification

Answer 19

the
increase of pollutant
concentration
throughout the
whole food chain.

Question 20

what is biomagnification also known as

Answer 20

bioamplification.

Question 21

how does biomagnification work

Answer 21

} Only 10% of energy is passed
from one trophic level to
another.
} This means a species has to
eat a large amount of the
species below it to survive.
} The species receives all of the
pollutants contained in all of
the organisms it consumed.
The pollutant is therefore
more concentrated in the
bodies of that species.

Question 22

Explain everything regarding DDT

Answer 22

Pesticide used in the 1900s.
◦ Banned in 1972.
◦ Seemingly harmless at first.
◦ Effects began showing up in high trophic levels
because of biomagnification.
◦ DDT has been linked to many conditions in
humans, such as diabetes.

Question 23

how is biomagnification dangerous in regards to food chains

Answer 23

◦ If the primary consumers are heavily damaged by a pollutant,
the secondary consumers will receive it even worse.
◦ Even if a pollutant only damages higher trophic levels, this
will create an imbalance in the ecosystem, and could damage
it severely.

Question 24

how is biomagnification dangerous in regards to humans

Answer 24

Because pollutants increase in concentration, humans receive

them at their most dangerous level.

Question 25

3 key problems regarding mercury

Answer 25

1) Mercury is a persistent toxic substance, it can build up, or
bioaccumulate, in living organisms; this can further effect
animals such as predatory fish, fish eating birds and
mammals through the process of biomagnification.
2)Mercury can be converted to methyl mercury (highly toxic)
mainly in lakes, waterways and wetlands. Methyl mercury
can cross the blood-brain and placental barriers that can
lead to a wide range of symptoms in organisms.
3) If water plants and small organisms take up the mercury
as food, it then moves through the food chain when
animals eat each other.