BIO 523 Exam 2

Which of the following groups were particularly outspoken and critical of Rachel Carson's book, Silent Spring?

chemical industry spokesmen

Endocrine Disruption

chemicals that can interfere with endocrine (or hormone) systems at certain doses. These disruptions can cause cancerous tumors, birth defects, and other developmental disorders. Any system in the body controlled by hormones can be derailed by hormone disruptors

The index termed Bioacculumlation Factor (BAF) is the ratio of ________ to ________.

conc in organism / conc in food

In tests of metal toxicity to soil invertebrates, which of the following metals was found in examples noted in your textbook and lecture to actually be beneficial to test organisms at very low concentrations?

copper

What organisms naturally synthesize the chemical BMAA(β-N-methylamino-L-alanine),which is a strong neurotoxin(ex. Lytico-Bodig Disease in Chamorro Islanders)?

cyanobacteria

Metallothioneins are protective proteins rich in the amino acid______, which contains sulfhydryl groups that bind to metals, resulting in sequestration and elimination.

cysteine

The egg cocoons of which of these animals can easily be counted as a measure of reproductive activityin soil microcosm testing?

earthworms

Which of the following pairs of biomarkers (Table 10.2) were shown to have the lowest specificity?

eggshell thinning/ inhibition of Acetylcholinesterase

What is the basis for estimating reproductive rates of springtail insects(Folsomia candida; Box 6.2 "Test on Springtails") in toxicology screening?

flooding the soil in their plastic vening machine cups, and counting the number that float to the surface

Which of the following anatomical structures in a fish has evolved an efficient counter-current exchange mechanism within the high surface area lamella of these structures?

gills

In fish, the two major sites of uptake from exposures to organic pollutants (Table 5.1) are:

gills and alimentary tract

In the dose/response curve (Figure 8.15) of the marine anti-fouling additive tributyltin (TBT) on a common intertidal bivalve (Mytilus edulis) was based on measuring which component of the bivalve's energy -nutrient allocation (i.e. the elements of a basic bioenergetics assessment)?

growth (production)

Which three actions largely account for the dramatic comeback in the number of Bald Eagles in the United States in the past four decades?

habitat protection as a Federal Endangered Species / banning useof DDT / public conservation measures

In the paper by Guengerich (2006) on cytochrome P450 enzymes, the author's reported that the levels (concentrations)of three different P450 enzymes in samples of liver tissue from 18 different humans (Fig 2 in paper):

had substantial variation between individuals

Organochloride insecticide residues were ______ in predator species of birds compared to either omnivore or herbivore (vegetation consumer) species [studies on British birds reported in your textbook and presented in class]

higher

In animals, the greatest concentrations of cytochrome P-‐450 enzymes are normally found in __________ tissue

liver

In the following figure from Guengerich (2006), what does the X (horizontal) axis represent?

liver samples of human subjects

Kidney clearance rates of caffeine, as expressed in half lives of hours to days, are ________ for infants compared to juveniles and adults.

lower

The addition of glucuronic acid to create a charged side group in a Phase 2 Reaction accomplishes what?

makes the substrate more polar (hydrophilic) for excretion

What greatly increases the ½ life (residence time) of caffeine in infants compared to juveniles and adults?

much slower kidney filtration rate

The Ames Assay is used to screen for:

mutagenicity

The Ames Test uses a special strain of Salmonella bacteria to estimate the ________ of chemical

mutagenicity

In the toxicity screen using Springtails (soil invertebrates in Phylum Collembala), what is the response measurement used to measure dose / response relationships?

number of offspring

In the toxicity screen using Springtails (soil invertebrates in Phylum Collembala), what is the response measurement used to measure dose/ response relationships?

number of offspring

In humans, the bluish / grayish skin discoloration of the condition termed Argyria is caused by over-exposures to ______________.

silver

How do gases, including pollutants, directly enter (and leave) the interior spaces of the leaf of a plant?

stoma (=stomates)

In the OECD Earthworm toxicity test (Box 6.1 description), what is the measure (metric) of toxicity for the 14 days (2 weeks) test populations of earthworms (note, another, more sensitive measure is used for longer testing intervals)?

survival (and mortality by difference)

In the Wissing Lab respirometer that I used for measuring oxygen consumption rates of bluegill sunfish for a thesis project at Miami University, solenoid valves on a timer closed off the 6.15 liter holding chamber from what key system component?

the "Bubbling" Tower

Perch exposed in an aquarium to an anti-anxiety drug (oxazepam), which is detectable in streamwaters (Swedish study in Science reported on in NPR report), caused which of the following changes in the fishes's behavior?

the fish became more daring (less fearful) and fed more quickly on food items placed in tank

What is the current main source of toxic contaminants in Picher and other areas of NE Oklahoma affected by mining operations (from the movie "Tar Creek")?

the large surface piles of tailings (referred to as "chat")

Which of the following are not associated with the OECD Earthworm Toxicity Test described in Box 6.1 and used as an example in lecture?

worms are fed a diet of cultured yeast and streptomycin antibiotic

in proteins, lead (Pb) can substitute chemically for which of the following pairs of ion?

zinc and calcium

List (don't attempt to explain) five different clinical symptoms and/or physiological mechanisms related to lead toxicity in humans

1. Encephalopathy 2. peripheral demyelination 3. Abdominal pain and irritability 4. chronic renal failure 5. pyuria

Neurotoxins that inhibit the enzyme AChE (acetylcholinesterase) result in:

delay in breakdown of acetylcholine and overstimulation of post-synapse receptors inability to bind acetylcholine on post-synapse receptors

The use of Warfarin and other related compounds as "Rhodenticides" used to poison rats and other rhodents is based on the ability of these compounds to weaken blood clotting by outcompeting _____________ in enzymes that carboxylate clotting proteins during the synthesis of these proteins in the liver.

Vitamin K

Infants, using kidney excretion, eliminate caffeine ________ juveniles and adults

a bit slower (5-10%) than

Antagonism Effect

a phenomenon wherein two or more agents in combination have an overall effect that is less than the sum of their individual effects

In a study of House Sparrows reviewed in Chapter 8 (Figures 8.10 and 8.11), what behavioral criteria was used to assess the effect of exposures to different levels of an organophosphate insecticide (Chlorfenvinphos)?

ability to handle seeds and the rate at which seeds were dropped

Scope for Growth is an important fate of an organism's ___________________ (from Fig. 8.14)

absorbed energy intake

Which of the following reactions represents Phase 1 xenobiotic chemical reactions that lead to reduced toxicity and transformation of hydrophobic (lipophillic)toxins?

addition of a molecular "handle" such as a hydroxyl group (OH-) to faciliate a Phase 2 conjugation reaction

Which of the following reactions represents Phase 2 xenobiotic chemical reactions that lead to reduced toxicity and transformation of hydrophobic (lipophillic) toxins?

addition of a polarized (charged) group such as glucuronic acid to facilitate elimination through pathways such as kidney glomerular filtration

When an organism is exposed to two different toxins, and the effects of the toxins, when combined, are equal to the sums of the separate affects of each toxin, the result is termed:

additive

Which of the following was not an example listed as a biomarker for human aging in the example discussed in lecture from a paper in Current Opinion in Biotechnology by Stanford scientists Zahn and Kim?

altered leukocyte cell counts

Glutathione is an important ______________ in cell molecular pathways.

antioxidant

Biomarker

any biological response to an environmental chemical at the individual level or below demonstrating a departure from the normal status. Thus biochemical, physiological, histological, morphological, and behavioral measurements may be considered biomarkers

In my joint work with University of Kansas researchers using a pond mesocosm system at the Nelson Environmental Studies Area near Lawrence, KS, what widely used agricultural chemical was tested for its affect on phytoplankton toxicity (i.e. blocking Photosystem 2 reaction of photosynthesis and enhancement a chlorophyll fluorescence)?

atrazine

Which of the following chemicals blocks electron transport in photosynthesis by binding to the plastoquinone-binding protein in the coupled set of Photosystem II reactions?

atrazine

The main function of Phase 1 and 2 detoxification reactions in animals is to:

attach polar side groups to hydrophobic toxins to promote safe excretion

In the Schalles and Wissing study with Bluegill Sunfish (Lecture 15), which bioenergetic variable was measured in response to feeding?

basal metabolic rate

What is the primary elimination pathway for toxins processed by vertebrate liver tissues?

bile duct transport for elimination with fecal wastes

Which system carries away most of the materials that a vertebrate liver is attempting to excrete (remove) from liver tissues?

bile ducts

Neurotoxins that block the post-synaptic receptors (ex. curare and atropine)

block the ability of acetylcholine to propagate a nerve signal transmission

Which of the following pairs of variables were used as criteria for the effects of the insecticide Chlorofenvinphos on House Sparrows?

change in body weight / seed dropping rate

In the atrazine experimental pond dosing experiment my group performed in collaboration with Dr. Frank (Jerry) Denoyelles at the University of Kansas's Nelson Experimental Area, what was our primary measure of the effects?

change in density of phytoplankton, based on optical light reflectance measures

What is the primary difference between studies of (1) Behavioral Toxicology and (2) Neurobehavioral Teratology?

#1 concerns toxic effects on juveniles and adults; #2 concerns effects toxic effects on fetal development

List five different things that you learned about U. of California Berkeley scientist Dr. Tyrone Hayes and his findings from the assigned article on his difficulties with a chemical manufacture, information presented on agricultural chemical use and effects in class lectures, and information in the video we watched in class on March 16.

1. Frogs in his lab that were exposed to atrazine had much less sperm in their testes than the control group 2. Some frogs that were born male were able to grow up into full functioning female frogs 3. Atrazine turns on aromatase that causes testosterone to be converted to estrogen 4. Levels of prostate cancer are higher in areas where men work in the factories that produce atrazine and 80% of them are african american 5. this generation's children will be exposed to over 300 synthetic chemicals before they leave the womb and most of them we are unsure of the biological impact of them

A freight train carrying tank cars with oil refinery products derails on a weakened bridge structure, and six tank cars fall into a Midwestern river and rupture. You are the leader of a team tasked with assessing the consequences of the spill. You are told to decide on five measurements (metrics, including fates, exposures, and biomarkers) you can quickly deploy (within the first 72 hours). What measures would you select -briefly describe and defend your choices:

1. In situ biological monitoring- if there is a presence of tubiflex worms then it is very polluted; however at the end of the 72 hours if there is a presence of mayfly larvae then this indicates the river may be more healthy again 2. Examine bivalves- 3. Water turbitity test to see how polluted the water is by dropping 4. 5.

List six different and important (at least to you) things you learned from watching the class video on Rachel Carson and her book Silent Spring

1. Rachel believed that we need to work with nature and not against it 2. DDT was thought of as safe and effective and was used to control the spread of disease during the war 3. Eagle and falcon populations were decreasing due to their inability to produce viable eggs 4. DDT poisioning of a bird sancturary spurred Rachel to write Silent Spring 5. The department of agriculture refused to share safe disposal methods for pesticides because they did not want the public to think it was unsafe 6. Rachel believed that the majority of control over insects was by other insects and by "playing God" we would upset the balance and eliminate the good insects like the gypsy moth

As discussed in class, list and briefly explain 3 different advantages of using mussels and other bivalves to monitor pollutants in coastal waters

1. They can show scientists the levels of metals and other pollutants in the ocean where they are 2. they are anatomically designed to filter the water 3. Long term studies can monitor the restoration efforts in those waters and they can see the changes in their protocols

PCB compounds have how many phenolic ring structures joined together?

2

Which of the following statements about human exposures and metabolism of lead is incorrect? A. Within blood, lead is primarily found in the serum (liquid) component B. Typically, 90% or more of absorbed lead is found in the skeleton (bone tissue) C. When ingested, children absorb a much greater percentage than adults D. Pulmonary absorption is possible, and most efficient when lead is bound to smaller inhaled particles (< 1 micron in diameter) E. Organic forms of lead (example tetraethyl lead) can be absorbed through the skin

A. Within blood, lead is primarily found in the serum (liquid) component

In the Standard Ames Assay to test the mutagenicity of chemicals, explain the reason(s) for using the following in the test protocol A. Salmonella strain with a mutation preventing biosynthesis of histidine B. chemical to be tested mixed at different concentrations with the test medium(an agar tube or gel plate) C. rat liver homogenate added to the agar medium

A. salmonella has a point mutation that makes them incapable of growing unless histidine is present. This will show that if there is growth on the petri dish then it was a result of a mutation from the genotoxic chemical B. The activated mutagen enters the bacterium and reacts with DNA to cause mutations; mutations in the operon for histidine biosynthesis that restore function ("reversions") allow the bacterium to grow on histidine-deficient medium, and result in visible colonies on the assay plate C. a rat liver homogenate is used to provide the cytochromes P450 necessary for activation of mutagens to their reactive forms

The three phases of the General Adaptation Syndrome (GAS) proposed by Dr. Hans Seyle in response to prolonged exposure to environmental stressors are:

Alarm Reaction /Resistance/ Exhaustion

Which of the following isotopes is of special concern and the main reason for the quarantine of dairy products in the region of the Fujushima Nuclear Power Plant crisis?

Cs-137

Which of the following pairs of toxicants has the lowest LD50 values (i.e. are lethal at the lowest doses; table in lecture 11)?

Dioxin (TCDD) / Botulinum toxin

What marine mammals were washing up dead on beaches of the Northern Gulf of Mexico this winter at much higher rates than normal?

Dolphins

In toxicity studies, which of the following measures represent the threshold for mortality increases compared to a control group?

LC50 (or LD50)

The finding (Cook et al. 2003 paper) that dixoins and other chlorinated, polycyclic hydrocarbons resulted in disruption of the normal function of aryl hydrocarbon receptors (AFR) was directly related to which of the following consequences:

Lake Trout larvae suffered severe developmental damage

Which of the following groups of stream macro invertebrates is considered one of the least tolerant to water pollutants?

Mayfly nymph (larvae)

What is the purpose of Project Mussel Watch?

Measuring toxin levels in bivalve tissues to look at temporal and geographic patterns

In Figure 6.1 in your textbook and discussion in lecture, the following terms were presented within the context of a dose (log of concentration in water of a toxin) and response (mortality as a percentage of test organisms compared to a control group): LOEC, LC50, and NOEC. With increasing X axis values (dose, or exposure concentration), what is the order in which these three effect measures appear?

NOEC, LOEC, and LC50

NOEC

No Observed Effect Concentration the concentration of a pollutant that will not harm the species involved, with respect to the effect that is studied. It is often the starting point for environmental policy NOEC can be determined only where LOEC is known; otherwise there would be no indica6ons of toxic concentra6ons

What coastal region lies directly at the end of the Rhine River, which receives all the pollutants carried down from the watershed, and experienced large die-‐offs of harbor seals (video "Race to Save the Planet-Do We Really Want to Live this Way")?

North Sea

The declaration in 1983 that a 200 mile stretch of the Hudson River below two General Electric plants was designated an EPA Superfund site was based on findings of extremely high levels of __________ in the river's sediments.

PCBs

Atrazine herbicide interferes with a key reaction in the _________ reactions in plant cells, leading to aninhibition of carbon fixation, rapid nutritional decline, and death of target plants.

Photosystem II

Atrazine herbicide interferes with a key reaction in the _________ reactions of photosynthesis, leading to an increase in photopigment fluorescence, inhibition of carbon fixation, and death of the plant.

Photosystem II

In the study of concentrations of PCBs found in the tissues of Chinook Salmon in waters of Northwest North America, which of the following sites stood out for having the highest levels of this toxin?

Puget Sound

Explain the concept "Scope for Growth" used in Chapter 8 and explained and illustrated in my lecture for March 8 and cite a single example from your textbook and/or lecture of how this concept can be used to determine sub-lethal effects of toxins.

Scope for growth is the surplus of energy available for growth beyond that required for maintenance. it is the allocation of nutrients for energy such as basal metabolism, detoxification, production (scope for growth), and excretion an example is the study that involved studying the effect on growth of TBT on the intertidal bivalves. this showed a higher scope for growth at lower levels of TBT

Larvae of Lake Trout, Salvelinus namaycush, were found to have extreme sensitivity to what xenobiotic (synthetic organic chemical) found in the Great Lakes of North America? (note: the chemical induced "blue sac" disease in the larvae)

TCDD-‐dioxin

Monooxygenase enzymes with cytochrome P450 reaction centers

The most common reaction catalyzed by cytochromes P450 insertion of one atom of oxygen into the aliphatic position of an organic substrate (RH) while the other oxygen atom is reduced to water:

Why are Killer Whales more at risk from organic contaminants in the marine environment than most other organisms in the coastal waters of the Pacific Northwest?

They are apex (top) predators

Which of the following chemicals is an acute toxin(mitochondrial poison)affecting the electron transport chain within the mitochondrial membrane, leading to hypoxia and rapid death?

hydrogen cyanide

What are the two main toxicological problems for Resident Killer Whales leading to population declines and their listing as Endangered (Southern group) or Threatened (Northern group)?

impaired immune functions / problems with reproduction & early development

Which of the following is an incorrect statement about Cytochrome P450 enzymes? A. they occur in the cells of virtually all organisms B. in animals, they are especially abundant in liver hepatocytes C. their presence can be induced when an organism is exposed to a xenobiotic toxin D. they are often involved in Phase 1 reactions ofmetabolic detoxification schemes E. in eukaryotes, they are primarily found lining the inner cell membrane

in eukaryotes, they are primarily found lining the inner cell membrane

In chapter 8 of our textbook, the authors described and discussed a toxicology study with soil-dwelling springtails (Collembola arthropods) exposed to copper provided as a "nutrient broth" to experimental soil systems. Starting with extremely low copper exposures, animal growth rates first _________ and then _________ with increasing copper doses and metal concentrations measured in the animals.

increased / decreased

Warfarin and other rodenticides kill vertebrates, including target rodents, because of which of the following molecular effects?

inhibition of the vitamin K cycle for synthesis of clotting proteins

Teratogens:

initiate damage at earlier stages of development (critical sensitive period)

Currently, what are synthetic organophosphorous compounds primarily used for?

insecticides

What toxic property do the following compounds share: Tabun, Sarin, Soman, GF, and VX?

interference with nerve synapse physiology

Pulmonary absorption of inhaled lead:

is more efficient with lead in small particles ( < 1 micron diameter)

What is the primary damage of exposure to the chemical warfare agent known as Mustard Gas?

its high level of sulfur and low pH result in blistering of exposed skin, air passageways, and lungs

The activity of the enzyme ALAD (aminolevulenic acid dehydratase) is strongly inhibited when a person is exposed to harmful levels of __________.

lead

Peripheral nerve demyelination, leading to prolonged nerve conduction times and partial paralysis of extensor muscles of the hands and feet (known as wrist and foot "drop") is a direct result of ______________ in humans.

lead poisoning

What is the major portal (entry point) for gaseous pollutants in the leaves of higher plants?

leaf stomata (=stoma)

In an example in Chapter 11 (environmental monitoring), Figure 11.2 showed severe declines in two of the three principal groups of ________________ growing on trees within the vicinity of a new aluminum plant in Wales (Great Britain) which airborne fluoride.

lichens

In Chapter 6 (Box 6.1) and a companion lecture, the use of earthworms for soil toxicity studies was presented. In addition to survivorship trials after 2 weeks of exposure to graded levels of toxicants, what other procedure was described (a procedure that is actually more sensitive to lower concentrations of toxins such as metals)?

number of reproductive cacoons (bearing eggs that develop in to juveniles)

Tabun, GF, and VX are examples of_____________.

organophosphorous nerve gases

The detoxification of the pesticide malathion (organophosphate molecule)by the enzyme carboxyesterase (Figure 9.5) is damaged by the ____________ effect on the reaction by monooxygenase enzymes in sensitive organisms (note, this is an example of a positive synergism where the damage in combination is greater than the sums of damage from separate interactions with the malathion and the monooyxgenase)

potentiation

What is the purpose of adding Rat Liver Homogenate to a test container in a Standard Ames Assay screening?

provide enzymes necessary to activate toxins to their "active form"

What is the principal source of caffeine found in significant quantities in natural waters, such as harbors, in the vicinity of Seattle (and other major cities)?

the passage of caffeine through the bodies of people in the metro populations, which can escape sewer systems with aging, leaky pipes and sewage treatment plant effluents

Which of the following statements about p450 enzymes is incorrect? A. these enzymes have high specifity (react with a single chemical substrate) B. these ezymes are found in all organisms C. these enzymes commonly are involved with Phase 1 detoxification of lipophilics D. these enzymes are inducible as a result of exposure to environmental chemical E. these enzymes are particular abundant in liver tissue (esp hepatocyte cells)

these enzymes have high specifity (react with a single chemical substrate)

What do eggshell thinning, acetylcholinesterase inhibition, and ALAD inhibition have in common(information in textbook and lecture)?

they are all biomarkers with high degrees of specificity to types of pollutants

What function do "Porin"proteins perform in gram-negative bacteria?

they serve as uptake "portals" for diffusion or facilitated transport of nutrients through the outer membrane (OM)

the major outcome of Phase 2 reactions in biochemical responses to chemical toxins is:

to increase the polarity and hydrophilic behavior of the substrate

Animals produce proteins termed ____________ which are produced in organs such as the gill, liver, and kidney to bind and remove certain toxic metals such as copper and cadmium.

tyrosine

What was the direct concern expressed in the title of "Silent Spring" in the landmark 1962 book by Rachel Carson's?

use of pesticides without proper precautions and care, could cause enough damage tonon-target wildlife, so that song-birds died off and their songs along with them