Ch 5

Question 1

Define Biomagnification

Answer 1

an increase in contaminant concentration from one trophic level to the next due to the ingestion of food

Question 2

What are some other reasons for the increase in concentration between prey & predators ?

Answer 2

1. Lipid concentrations may be higher in predators
2. Metabolic differences
3. life span - predators usually live longer
4. size - predators often larger
5. growth dilution - prey often grow faster, resulting in more growth dilution

Question 3

True or false - Trophic status is sometimes not easily defined & may result in poorly defined hypothesis

Answer 3

TRUE

Question 4

True or false - Trophic transfer does not necessarily mean biomagnification

Answer 4

TRUE

Question 5

What two things are required for something to be classified as biomagnification

Answer 5

requires a transfer through multiple trophic levels AS WELL AS an increase in concentration

Question 6

What is an environmental disaster which is an example of biomagnification

Answer 6

Itai-Itai disease - cadmium went from the soil to the rice & transferred to the people

Question 7

define biominification & what does it depend on

Answer 7

contaminant concentration decreases with trophic transfer - depends on site of action/deposition to some extent

Question 8

True or false - contaminant concentration will never sat the same for all trophic levels

Answer 8

FALSE - it can

Question 9

with which two methods can assimilation using a single radioactive tracer be used

Answer 9

1. amount of contaminant present present in tissue after reaching steady state divided by total amount fed
2. amount of tracer (ingested - egested) divided by amount ingested

Question 10

Describe the twin tracer method

Answer 10

compare the amount of a radio-labeled substance that will be assimilated & inert radio tracer
feed both substances & follow the appearance of the inert tracer in the faces/urine
Once all inert tracer is accounted for can look for assimilation of the substance of interest