Transcript Review - cloudfront.net

Review
1. What is the main difference between bioaccumulation and biomagnification?
Bioaccumulation is within an organism and biomagnification is within a food chain
2. Why don’t farmers use biopesticides?
Slow and less effective
3. Explain what a pesticide is.
Synthetic chemical created to kill one or more targeted pests
4. Describe TWO major categories of pesticides. For example Insecticides-kills insects and other
arthropods. (Do NOT use insecticides as one of your choices).
Fungicides and herbicides
5. What are two advantages and two disadvantages to using synthetic pesticides?
Saves lives (Malaria/Typhus/West Nile Virus)/Increase crop yields (support larger population)
Environmental pollution (Water, air soil)/Promotes genetic resistance in target species (more
or new pesticides needed for same job)
6. Name a metal and a chemical the is highly persistent and biomagnifies?
Mercury or lead/DDT
7. Name a fish, mammal and a bird that may contain high levels of POPS? Where do you find
them in the food chain?
Salmon/swordfish-Dolphin-Osprey
8. Explain how bacteria could develop resistance to a bactericide.
1. When a bactericide is applied, most of the targeted bacteria die, but some may survive.
2. The bacteria that survive have some genetic variation that gives them a natural resistance
and pass that resistance (gene) to their offspring.
3. After several generations only a population of resistant bacteria remain.
9. Give two examples of how bacterial resistance can economically impact orchard owners.
1. Unable to kill the bacteria some trees may die reducing orchard profits from fruit.
2. Dead trees must be replaced at a cost to the farmer.
3. Use of new or more bactericides will cost the farmer more reducing profits.
10. Describe an example of how the development of bacterial resistance can affect human
health.
1. The use of antibiotics by humans can cause our pathogens to become resistant to current
medications making disease organisms stronger and harder or impossible to kill with
current medications. This may cause diseases to last longer or kill humans that in the past
were easily treated. (make sure to finish all medications no matter how much better you
feel)
Review
1. An experiment is performed to test the toxicity of copper sulfate (CuSO4) using brine shrimp
as a test organism. Six different concentrations CuSO4 of solution are prepared in separate
Petri dishes, and 100 brine shrimp are places in each dish. After 48 hours, the number of
brine shrimp that have died is counted and recorded. The results of this experiment are
shown in the table below.
CuSO4 Concentrations (%)
Number of Dead Brine Shrimp
<0.0001
10
0.001
10
0.01
20
0.1
55
1
90
10
100
Plot these data on the blank semi-log graph provided below. Draw a smooth curve through the
data points to illustrate the overall trend of the data. Label the Y axis with number of dead
brine shrimp and the X axis with concentration
Threshold level of
Toxicity
0.0001
0.001
0.01
0.1
1
10
LD50
2. Explain the meaning of LD50 (ED50). What is the LD50 concentration of CuSO4 for brine
shrimp?
LD50 is the amount or dose of a chemical or toxic substance that kills
half of the test population. 0.07 – 0.09 %
3. Explain the meaning of the term “threshold level of toxicity”. What is the threshold level of
toxicity of CuSO4 for brine shrimp? Label this point on the graph.
The dose below which no toxic or lethal effects are observed and/ or
above which the toxic or lethal effects are apparent.
4. Provide one argument for extending these toxicity results to humans and one argument
against doing so. Since the copper sulfate was toxic to the brine shrimp it is
reasonable to assume that it might be toxic to humans
5. Name and describe ONE U.S. federal law OR ONE international treaty that focuses on the use
of pesticides.
Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA): States what must be on a pesticide
label & requires registration of all pesticides.
Food Quality Protection Act of 1996 (FQPA): The safety standards for new pesticides used on
foods (especially kids)
Endangered Species Act (ESA): Requires the EPA to assess the risk of pesticides to threatened or
endangered species and their habitats.
PERSISTENT ORGANIC POLLUTANTS (POPSTREATY): International treaty to phase out 12 organic
persistent pollutants known as the “dirty dozen” such as DDT and PCBs
Review
1. Discuss TWO alternatives to the use of pesticides
Developing GMF (GMO) modified to be pest resistant
Utilize crop rotation to keep pests in one area
Use biological controls to kill or parasitize the pests
Use of pheromones to attract and trap pest of disrupt their reproductive cycle
2. Persistent organic pollutants (POPs) are toxic chemicals that can cause health issues in
humans and wildlife. What makes POPs so dangerous when released into the environment?
POPs are persistent and stay in the environment a long time, The bioaccumulate and
biomagnify, and the travel long distances by air and water
3. Explain two ways in which POPs are harmful to humans and wildlife.
They are endocrine disruptors that can feminize or masculine humans, cause reproductive
abnormalities, they can cause cancer, and they can cause nervous system disorders.
6. Explain the purpose of DDT and issues with its use.
DDT was used mainly as a pesticide to kill mosquitoes. The issues with its use include
bioaccumulation, biomagnification, egg shell thinning in many predatory birds.
7. One strategy for dealing with agricultural pests is integrated pest management (IPM)
Describe IPM. As part of your description, include TWO specific pest-control approaches that
are part of IPM.
IPM uses a combination of biological, chemical, and physical means to control pests.
Introduce predators to the pests/Rotate crops/Vacuum pests/Use narrow-spectrum or less
persistent pesticides
8. Identify one environmental benefit to IPM.
Reduction of pesticides into areas other than farmlands/Reduction of death of non-target
organisms/reduces bio (A and M) of pesticides
9. Describe TWO agricultural practices, other than those involving pest control, that increase
crop yields.
Irrigation/Fertilizers/GMO
Review
1. In 1840, the life span of the average American was just 37 years. Today, it is approximately 77
years, with much of the increase in average life span occurring in the last 50 years. List TWO
events that have occurred within the last 100 years that could account for the increase in human
life span. Industrialization, Modern medicine, Modern agriculture, Sanitation, and clean
water supplies
Diseases on the Rise!
Despite the fact that many old diseases have been effectively controlled by the use of antibiotic
and vaccines, it appears that the world is becoming more vulnerable to the outbreak of
relatively new diseases (SARS) and West Nile Fever, and the reemergence and spread of old
diseases such as malaria, cholera and tuberculosis. According to epidemiologist Dr. Amodie, “it
is not possible to protect the health of Americans without addressing the problems of infectious
diseases on a global scale.” The threat of the emergence and spread of newly arising infectious
diseases has become a dangerous reality. These new diseases could become the endemic
diseases of tomorrow.
2. For one new disease and one old disease named in the article above, explain how the disease
is transmitted through the human population and describe an effective method for controlling
the spread of the disease.
SARS/directly from animals to humans or humans to humans by respiratory droplets/Not have
animals close to humans-destroy infected animals or wear facial masks and wash hand
frequently
Cholera/Ingestion of contaminated water or food with cholera bacteria from human fecal
matter or directly from your contaminated hands/Boil water to kill pathogen-provided
pathogen free water supply-provide sanitary collection and treatment of sewage-wash hands
TB/Spread by respiratory droplets/Immunization-Quarantine-Treatment with antibiotics
3. For one of the two diseases you chose in part (A), identify one environmental factor that
contributed to the emergence or reemergence of the disease and explain how that factor
influenced incidence of the disease.
SARS/TB-High population density of humans gives increased likelihood of transmission
Cholera-lack of sanitation or pathogen free water increases transmission of pathogen
Review
1. Currently, about 3.3 billion people-half of the world’s population are at risk of malaria. Every
year, this leads to about 250 million malaria cases and nearly 1 million deaths, with people living
in the poorest countries being the most vulnerable. Malaria is especially serious in Africa,
where 20% of childhood deaths are caused by the disease (i.e., every 30 seconds a child dies
from the disease).
A. Explain how malaria is transmitted through the human population.
Malaria is naturally transmitted through the bite of the female Anopheles mosquito. When
the mosquito bites an infected individual some of the malaria parasites are taken with the
blood meal. These parasites reproduce and make their way into the mosquito’s saliva that is
injected into the next person.
B. Identify TWO environmental factors that contribute to the emergence of malaria and explain
how those factors influence the increase in the incidence of the disease.
A decrease in the population of mosquito predators which correlates to increased mosquito
population/AN in crease in the human population density allowing more opportunities for
transmission/Changes in global temperature allow new habitat for mosquitoes and
transmission
C. Traditionally, the spread of malaria was controlled by the use of pesticides such as DDT.
However, DDT and other pesticides often have negative environmental impacts. A promising
alternative to the use of pesticide is biological control. Describe biological control and provide
ONE biological control method for controlling the spread of the disease.
Using natural enemies against them like mosquito fish, dragonflies, or microbial pathogens.
The above is true for West Nile Virus also transmitted by various mosquito species