Podcast
Questions and Answers
DDT primarily affects what in insects?
DDT primarily affects what in insects?
- Reproductive system
- Sodium channels in neurons (correct)
- Respiratory system
- Digestive system
DDT was never widely used to control mosquito populations.
DDT was never widely used to control mosquito populations.
False (B)
When was DDT banned in the United States?
When was DDT banned in the United States?
- 1982
- 1992
- 1972 (correct)
- 1962
The WHO has completely stopped recommending DDT for malaria control.
The WHO has completely stopped recommending DDT for malaria control.
What was the effect of a DDT spray campaign on malaria incidence in Italy shortly after World War 2?
What was the effect of a DDT spray campaign on malaria incidence in Italy shortly after World War 2?
DDT usage always correlates with a decrease in malaria incidence.
DDT usage always correlates with a decrease in malaria incidence.
What does Anopheles gambiae get from animals when they bite?
What does Anopheles gambiae get from animals when they bite?
Anopheles gambiae are known to carry the disease ______.
Anopheles gambiae are known to carry the disease ______.
Match the population of Anopheles gambiae to their relative susceptibility to DDT:
Match the population of Anopheles gambiae to their relative susceptibility to DDT:
What is the name of the family of related enzymes that break down fat soluble chemicals in insects?
What is the name of the family of related enzymes that break down fat soluble chemicals in insects?
The acronym for Glutathione S-transferases is ______.
The acronym for Glutathione S-transferases is ______.
What type of compound is DDT, in terms of its solubility?
What type of compound is DDT, in terms of its solubility?
GST variants cannot differ in their ability to break down DDT.
GST variants cannot differ in their ability to break down DDT.
If the offspring of mosquitoes collected in the field were shown to have high DDT resistance, what can biologists conclude about the population?
If the offspring of mosquitoes collected in the field were shown to have high DDT resistance, what can biologists conclude about the population?
Differences in GST amounts and activities suggest a ______ may have occurred that detoxifies DDT.
Differences in GST amounts and activities suggest a ______ may have occurred that detoxifies DDT.
For DDT to be effective as an insecticide, what part of the insect must it interact with?
For DDT to be effective as an insecticide, what part of the insect must it interact with?
Permethrin affects the digestive system of insects.
Permethrin affects the digestive system of insects.
Permethrin is used in personal protection against insect ______.
Permethrin is used in personal protection against insect ______.
Based only on the data provided, is permethrin effective at killing A. gambiae?
Based only on the data provided, is permethrin effective at killing A. gambiae?
If an enzyme that detoxifies permethrin is inhibited, one would expect lower mortality in a permethrin treatment.
If an enzyme that detoxifies permethrin is inhibited, one would expect lower mortality in a permethrin treatment.
What result is observed the earliest when using insecticides to kill a susceptible control population of mosquitoes?
What result is observed the earliest when using insecticides to kill a susceptible control population of mosquitoes?
If sodium channel genes evolve in mosquito populations, it is possible for mosquitoes to become resistant to both DDT and ______.
If sodium channel genes evolve in mosquito populations, it is possible for mosquitoes to become resistant to both DDT and ______.
What does it mean if a mosquito population is described to be resistant to a pesticide?
What does it mean if a mosquito population is described to be resistant to a pesticide?
Resistance to permethrin makes a mosquito population more susceptible to DDT.
Resistance to permethrin makes a mosquito population more susceptible to DDT.
What is the name of the enzyme whose activity is affected by carbamate insecticide exposure in mosquitoes?
What is the name of the enzyme whose activity is affected by carbamate insecticide exposure in mosquitoes?
After exposure to a carbamate insecticide, Acetylcholinesterase (AChE) activity drops quickly in _______ mosquito homogenates.
After exposure to a carbamate insecticide, Acetylcholinesterase (AChE) activity drops quickly in _______ mosquito homogenates.
What was the function of testing the S2 cell line relative to acetylcholinesterase activity?
What was the function of testing the S2 cell line relative to acetylcholinesterase activity?
Testing different types of cells is unnecessary when characterizing resistance to insecticides.
Testing different types of cells is unnecessary when characterizing resistance to insecticides.
According to the evolutionary tree of Culex pipiens, how many times did resistance evolve in these two subspecies?
According to the evolutionary tree of Culex pipiens, how many times did resistance evolve in these two subspecies?
The evolutionary tree of Culex pipiens populations uses the _______ DNA sequence.
The evolutionary tree of Culex pipiens populations uses the _______ DNA sequence.
Which statement best fits the impact of the use of DDT insecticide on public health?
Which statement best fits the impact of the use of DDT insecticide on public health?
Mosquitoes would not benefit from developing insecticide resistance in their populations.
Mosquitoes would not benefit from developing insecticide resistance in their populations.
DDT, Dichloro-diphenyl-trichloroethane, is the first ever ______ insecticide.
DDT, Dichloro-diphenyl-trichloroethane, is the first ever ______ insecticide.
Flashcards
What is DDT?
What is DDT?
A synthetic insecticide first used in the 1940s to control insects.
How does DDT affect neurons?
How does DDT affect neurons?
DDT affects this part of cells in insects, leading to paralysis and death.
Why DDT was eventually banned
Why DDT was eventually banned
Long-term health and environmental problems caused countries to stop using it.
What is Anopheles?
What is Anopheles?
Signup and view all the flashcards
Response of Anopheles to DDT
Response of Anopheles to DDT
Signup and view all the flashcards
Resistance to DDT, offspring in field
Resistance to DDT, offspring in field
Signup and view all the flashcards
What are GSTs?
What are GSTs?
Signup and view all the flashcards
Activity of each GST variant?
Activity of each GST variant?
Signup and view all the flashcards
Allele to detoxify DDT
Allele to detoxify DDT
Signup and view all the flashcards
What is permethrin?
What is permethrin?
Signup and view all the flashcards
PBO effect on permethrin
PBO effect on permethrin
Signup and view all the flashcards
Laboratory control
Laboratory control
Signup and view all the flashcards
Resistance in mosquitos
Resistance in mosquitos
Signup and view all the flashcards
Differences in cell line.
Differences in cell line.
Signup and view all the flashcards
Interpreting evolutionary tree
Interpreting evolutionary tree
Signup and view all the flashcards
Study Notes
- Chapter 20.4 explores evolution in a lifetime, focusing on pesticide resistance in insects, herbicide resistance in weeds, and antibiotic resistance in bacteria.
DDT: Dichloro-diphenyl-trichloroethane
- DDT was the first synthetic insecticide.
- It affects sodium channels in neurons.
- DDT was widely used globally from the 1940s to 1980s.
- Its applications included controlling mosquito populations and agricultural pests.
- Long-term health and environmental effects led to bans in the US in 1972 and in the EU in 1986.
- The WHO still uses DDT indoors for malaria control.
- After a DDT spray campaign began in Italy, the cases of malaria saw a steep decline between 1945 - 1949.
DDT and Mosquitoes
- The relationship between malaria incidence and DDT use in India from 1965-78 shows as DDT use increased over time, malaria saw a sharp increase.
Mortality of Anopheles gambiae Populations to DDT
- Anopheles gambiae from Gambia are more susceptible to DDT than those from Tanzania.
- For a 50% mortality rate, the Gambian population had a concentration of 0.017, while the Tanzanian population was 0.339.
- For a 90% mortality rate, the Gambian population had a concentration of 0.040, contrasted with 1.160 for the Tanzanian population
- Resistance evolves since the offspring are from mosquitos collected in the field and had no prior exposure,
GSTs: Glutathione S-transferases
- GSTs are a family of related enzymes.
- The key function is to breakdown fat-soluble chemicals.
- DDT is a fat-soluble compound.
- A mutation changed the allele to one that detoxifies DDT faster.
- The mass of each variant of GST saw different amounts in samples taken from Gambia vs Tanzania
- The ability of each variant to breakdown DDT saw different rates between the two areas
Permethrin
- Discovered in 1973, permethrin affects insect nervous systems.
- Used broadly to control insect populations, it is also used in personal protection.
- In time, the mortality rate of A. gambiae exposed to 0.5% permethrin was different by area; Kenyan population, Kenyan population w/ PBO, Tanzanian, and the laboratory control population.
- The permethrin-resistant population is somewhat resistant to DDT.
- 50% mortality occurs earliest in the susceptible control population.
Acetylcholinesterase Activity
- Acetylcholinesterase activity of resistant and susceptible mosquitoes was studied after exposure to a carbamate insecticide.
- AChE drops quickly in susceptible mosquito homogenate.
- It was a control to show there wasn't any unknown ACHe activity when testing the S2 cell line.
- Comparison of the responses of mosquito homogenate and S2 cells with ACHe inserted.
Evolutionary Tree of C. pipiens Populations
- The tree is made up of populations from around the world, belonging to two subspecies, using the acetylcholinesterase DNA sequence.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
