9. Molecules to Populations

Question 1

What are ecologically relevant measures?

Answer 1

• Ecologically relevant measures are what ecotoxicologists are interested in
• They are the measures of the effects at the level of the population

Question 2

How are ecologically relevant measures generally measured as? (3)

Answer 2

• Growth/development
• Reproduction
• Survival

Question 3

How can we link the different levels of populations together (from chemicals to communities)?

Answer 3

Using biomarkers

Question 4

What are biomarkers?

Answer 4

a biological response to a chemical or chemicals that gives a measure of exposure and sometimes, also of toxic effect

Question 5

What are the 3 defining characteristics of a biomarker

Answer 5

• Measurable (quantitative)
• Biological (response)
• A marker for something else (a predictor)

Question 6

Are bioindicator species biomarkers?

Answer 6

no

Question 7

Examples of biomarkers in human health (5)

Answer 7

• blood pressure
• BMI
• cholesterol
• body temperature
• blood sugar

Question 8

What can be used as a biomarker for exposure to DLCs?

Answer 8

CYP1A levels.
Higher tissue levels of DLCs (assessed here as sumTEQs, x-axis) are correlated with higher levels of CYP1A induction (assessed here as EROD activity, y-axis)

Question 9

What can be used as a biomarker for exposure to estrogenic compounds?

Answer 9

• Vitellogenin (VTG) is an egg yolk precursor protein
  
  • Normally only produced in females during oocyte maturation
    ○ very low background levels in males
• Effective biomarker for estrogenic chemicals