Midterm Flashcards

1
Q

What the two physico-chemical properties influencing chemical fate?

A

Persistence and mobility.

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2
Q

What are the three types of life tables?

A

Cohort, horizontal, and survival

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3
Q

a collection of fragmented subpopulations is a __________

A

metapopulation

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4
Q

what does the glutathione s-conjugate export pump do?

A

it removes glutathione conjugates from cells

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5
Q

In Risk Characterization, what is the formula for Hazard Quotient

A

dose/toxicity reference value, greater than 1 means there’s a risk

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6
Q

What is biotransport?

A

It is when a contaminant is able to move around an ecosystem because it is in an organism. Seabird guano is an example of this.

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7
Q

What are four biological traits the contribute to higher concentrations in predators?

A

high lipid content, longer lifespan, larger body size, slower growth rates

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8
Q

What is a biomarker of dioxin exposure?

A

Induction of CYP1A4 and CYP1A5

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9
Q

why does increased temperature typically increase bioaccumulation rate?

A

Because the increase in temperature usually causes increased feeding and growth, thus increased uptake

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10
Q

what is assimilation efficiency?

A

the proportion retained of total ingested.

= mass in tissue / mass in food

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11
Q

which has higher absorption and distribution? inorganic mercury or organic mercury?

A

organic mercury

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12
Q

what is S34 used to indicate?

A

its a good indicator of food source, rather than trophic level

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13
Q

does bioaccumulation usually increase or decrease with increasing pH?

A

it usually decreases with increasing pH

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14
Q

What is N15 used to indicate?

A

its the best indicator of trophic status and marine input. average increase of 3.4% per trophic level

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15
Q

What is the formula for daily dose of exposure?

A

Concentration in food x food intake rate x area use factors divided by body mass

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16
Q

what are the light isotopes

A

C12, N14, S32

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17
Q

Name this formula:

Nt = Noert

A

exponential growth formual

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18
Q

ppb

A

ug/kg ng/g ug/L

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19
Q

What is R0?

A

net reproductive rate. number of females born to a female in her life time

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20
Q

What are they heavy isotopes?

A

C13, N15, S34

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21
Q

Name four routes of chemical uptake into cells

A

passive diffusion, active transport, phagocytosis, and facilitated diffusion

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22
Q

Bioaccumulation is the net consequence of ____ and ____.

A

uptake and elimination

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23
Q

what is dx

A

the number dying between x and x + 1

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24
Q

What is the formula for biomagnification factor

A

= [in organism] / [in diet]

>1 means biomagnifying

<1 means trophic dilution

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25
Q

What formula is this

A

Logistic growth model

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26
Q

what is the most widespread sublethal effect?

A

behaviour

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27
Q

what is bioavailability?

A

the fraction of contaminant that is available for uptake by organisms and capable of exerting a toxic effect; also, the fraction of a contaminant that is absorbed across biological membranes and assimilated into tissues

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28
Q

Boomerang Paradigm

A

What you throw away may come back to harm you” DDT, MeHg

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29
Q

what is Tc?

A

Mean generation time

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30
Q

What is r? how is it calculated?

A

r is the intrinsic growth rate, it is relative to 0

r = (birth rate - death rate)

r = 0 = no growth

r > 0 = population growth

r < 0 = population decline

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31
Q

what is isotopic discrimination?

A

lighter isotopes (C12, N14, S32) are eliminated from organisms more readily during trophic exchange than heavier isotopes (C13, N15, S34)

So we find heavier isotopes up the food web

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32
Q

what is qx

A

mortality rate between x and x + 1

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33
Q

what do p-glycoproteins pumps do? and what is its shorthand?

A

P-gp. it is a cell membrane protein that pumps many foreign substances out of cells

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34
Q

Life Table Response Experiments (LTRE) provide a measure of effects on ______ ________ _______

A

population growth rate

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35
Q

What is phase 1 biotransformation

A

trying to make compound more hydrophilic by adding functional group

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36
Q

What are the three major classes of contaminants?

A

Metals and metalloids, organic contaminants, and radionuclides.

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37
Q

Define population within the realm of ecotoxicology

A

a group of contemporaneous individuals of the same species occupying a habitat with patches differing markedly in the capability to foster survival, growth, and reproduction

38
Q

What are the two most useful ways of classifying contaminants?

A

By chemical structure and mechanism of action.

39
Q

what is depuration

A

the experimental procedure of placing an organism into a clean environment where the contaminant concentration will decrease

40
Q

What is the typical length of an acute toxicity test?

A

Less than 96 hours.

41
Q

what is the common mode of action in dioxin-like compounds?

A

mediated by aryl hydrocarbon receptor

42
Q

Xenobiotic

A

A foreign substance that is not part of the normal biochemistry of the organism.

43
Q

Explain how increasing organic carbon content in water can both increase and decrease bioavailabilty

A

it can increase bioavailabilty because the turbid water will have less light penetration, less photolysis.

it can decrease bioavailability because the organic matter can complex with the contaminants

44
Q

what is biomineralization

A

metal biotransformation whereby, for example, lead or cadmium are incorporated inertly into bone or exoskeleton

45
Q

ppm

A

mg/kg ug/g mg/L

46
Q

Toxicant

A

Toxic substances that are produced by or are a by-product of human-made activities.

47
Q

what is lx?

A

age specific survival, proportion surviving to that age class

48
Q

what is mx?

A

age specific fecundity, mean number females born to a female in that age class

49
Q

For BCF, which source of accumulation does it exclude? Respiration, dermal, or diet?

A

Diet

50
Q

Toxin

A

Substance produced naturally, i.e. by a plant or animal/ Protein based

51
Q

what is C13 used to indicate?

A

it can be used as an indicator of trophic structure and carbon input

52
Q

What are five disadvantages to behaviour based endpoints?

A
  1. the dose-response relationship isn’t great
  2. extrapolation from lab to field isn’t great
  3. large individual variation in response
  4. some behavioural effects may not be directly related to fitness
  5. difficult to relate effects to specific chemical(s)
53
Q

Differentiate adsorb and absorb

A

Adsorption adheres to, absorption goes in

54
Q

Do gases or liquids have higher vapour pressure?

A

Gases

55
Q

Contaminant

A

Chemical or element that exceeds normal background levels; it may or may not cause environmental harm

56
Q

Dose

A

Total amount of a substance administered to, taken, or absorbed by an organism.

57
Q

Mechanism of Action

A

A set of molecular targets of a drug or contaminant and the receptors and enzymes involved. eg. Acetylcholinesterase inhibitor.

58
Q

Dilution Paradigm

A

The solution to pollution is dilution

59
Q

What is the most toxic toxicant?

A

TCDD

60
Q

define autoecology

A

the study of an individual organism or species and its relationship to the physical, chemcial and and biological environment

61
Q

what is the difference between a leslie and a leftkovitch matrix?

A

a leslie matrix is age structured, a leftkovitch is life stage structured

62
Q

Define allometry and how it is related to ecotox

A

the size of an organism influences feeding rate, metabolic rate and thus uptake, biotransformation and elimination processes

63
Q

name three types of elimination pumps

A

glutathione s-conjugate export pump, OAT, p-glycoprotein pump

64
Q

What are nutrient subsidies?

A

This has to do with the movement of material from one habitat to another. Emergent insects are nutrient subsidies because they take from aquatic environments and give them back to the terrestrial environment.

65
Q

Which LC50 is most toxic? a) 280 b) 0.41 c) 5.3 d) 0.003 e) 35

A

d) 0.003.

66
Q

Pollutant

A

Chemical or element that exceeds normal background levels and causes environmental harm.

67
Q

What is the most toxic toxin?

A

Botulinum

68
Q

what are two enzymes are affected by dioxin responsive genes?

A

CYP1a4 and CYP1a5, which are involved in phase I and phase II metabolism

69
Q

What are contaminant subsidies?

A

Similar to nutrient subsidies, but with contaminants. Salmon are contaminant subsidies because they bring contaminants from the ocean into pristine Alaskan lakes

70
Q

what is the relationship between r and λ?

A

r = ln λ

or

λ = er

71
Q

Do higher or lower trophic levels have higher assimilation efficiencies?

A

Higher trophic leves

72
Q

what information do vital rates provide?

A

life cycle events such as rates of birth, growth, fecundity, maturation and mortality

73
Q

What is the formula for bioaccumulation factor?

A

concentration in organism / concetration in media

(at steady state)

74
Q

what is an isotopic fingerprint?

A

its the ratio of heavy vs. lighter stable isotopes compared against a standard (C-13/C-12, N-15/N-14, O-18/O-16)

75
Q

Name three types of metal biotransformation

A

biomethylation, metallothionein binding, biomineralization

76
Q

what are two synonyms for biomagnification?

A

bioamplification and trophic enrichment

77
Q

What is the theory of global fractionation?

A

most volatile chemicals, such as HCB, HCH, travel to the highest latitudes, while less volatile compounds, such as DDT, are less readily distilled and tend to remain near their source region

78
Q

Which species’ LD50 indicates greatest sensitivity? Guinea pigs = 0.61 Rat = 22 Mice = 283 Rabbit = 115 Monkey = 50

A

Guinea pigs with 0.61.

79
Q

What is the typical length of a chronic toxicity test?

A

Ideally minimum 10% of organism’s lifespan.

80
Q

Differentiate “in suspension” and “in solution”

A

Something in suspension will fall to the bottom, something in solution is dissolved.

81
Q

what does the exposure profile do?

A

it quantifies the magnitude, and spatial and temporal pattern of exposure for the scenarios developed during problem formation

82
Q

What is arctic haze

A

its a mixture of aerosols containing acidifying SOx, NOx, coarse particles of soot, heavy metals PAHs and PCBs

83
Q

what is selyean stress/general adaptation syndrome?

A

the non-specific response of the body to extraordinary demands made upon it: alarm, adaptation, exhaustion

84
Q

does toxicity and bioavailabilty usually increase or decreases with increasing water hardness?

A

it decreases

85
Q

Mode of Action

A

Broad set of biological responses involving processes or biochemical pathways that are affected in an organism. e.g. cell signalling, DNA synthesis, oxidative phosphorylation.

86
Q

Name two chemical properties that contribute to biomagnifcation

A

persitence and lipophilicity

87
Q

what is λ? When is it used? whats the formula?

A

the finite growth rate, functions in discrete time steps, when you want to know what is happening between years

Nt+1 = λNt

lambda = 1 = no growth

lambda > 1 = growth

lambda < 1 = decline

88
Q

what is biomethylation

A

metal biotransformation whereby an ethyl or methyl group is added to a metal

89
Q

ppt

A

ng/kg pg/g ng/L

90
Q

Concentration

A

Quantity of a material or substance contained in unit quantity of a given medium or system.