Which statement best describes the evolution of pesticide resistance in a population of insects?
Science g9 ch 7 sec 2 revision10 1 2021
The physical and behavioral characteristics of an organism are determined by its genes. Individuals pass on special combinations of genes to their offspring as they reproduce. Individuals with various physical and behavioral characteristics thrive in various settings. Individuals that have genes that help them survive are more likely to pass these genes on to their children than the rest of the population. The gene pool refers to the genetic makeup of a population. Natural selection is a mechanism that affects the genetic makeup of the population over time.
Fruit growers have used artificial selection to take advantage of the gene pool’s natural variability with the aid of plant breeders. The first step in this process is to decide which traits are desirable, such as taste, colour, tolerance, or pest resistance. Once desirable traits have been found, traditional breeding or genetic engineering may be used to integrate them into new crop varieties. Apples, for example, have been bred to produce a few varieties resistant to apple scab. Fruit crop varieties have a natural range of resistance to various pests and diseases, even without specific breeding efforts. When monocultures of single varieties are planted, production efficiency is exchanged for pest resistance diversity.
Plant health pyramid
Pesticide resistance is increasing at an unprecedented pace. However, evolutionary theory suggests that we can slow the spread of pesticide resistance genes by establishing safe havens for non-resistant insects.
Insects gnaw away at crops in the fields and the razor-thin profit margins they provide. What can a farmer do? Of course, spray. Grow pesticide-producing crops, or plant crops that have been genetically modified to produce their own pesticides.
However, according to evolutionary theory, these solutions will not last forever. Since pest insects have short generation times and large populations, they evolve rapidly. Insects resistant to pesticides will develop if pesticides are widely used or if pesticide-producing plants are widely planted in fields. Any major class of insecticide used in agriculture has been shown to have some level of resistance. 1
Is there some way to stop resistant genes from spreading? We should provide safe havens for non-resistant insects (and their non-resistant genes! ), according to evolutionary theory. These safe havens are known as refugia, and they are pesticide-free (sprayed or plant-produced) fields near pesticide-producing crops.
How does insecticide resistance happen?
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This informative book, based on a symposium sponsored by the Board on Agriculture, examines the issue of pesticide resistance, proposes new methods to track, regulate, or prevent resistance, and identifies the public policy changes needed to protect crops and human health from pesticides’ ravages. The book brings together the most recent findings from a variety of fields, including entomology, genetics, plant pathology, biochemistry, economics, and government policy. It also proposes research directions that may lead to solutions to potential problems. A glossary gives supplementary information to the reader.
12. insecticide resistance – molecular level
The use of pesticides will artificially select for pests that are resistant to them. The first generation in this diagram has an insect that has developed a high level of resistance to a pesticide (red). Since sensitive pests (white) were selectively killed after pesticide application, their descendants make up a greater proportion of the population. Resistant pests can make up the majority of the population after repeated applications.
Pesticide resistance refers to a pest population’s reduced tolerance to a pesticide that was previously successful in controlling the pest. Pesticide resistance evolves through natural selection, with the most resistant individuals surviving and passing on their acquired heritable changes traits to their offspring. 1st
Resistance has been documented in all types of pests (crop diseases, weeds, rodents, and so on), with ‘crises’ in insect control occurring shortly after pesticide use began in the twentieth century. Insecticide resistance is described as “a heritable change in the sensitivity of a pest population that is reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for that pest species” by the Insecticide Resistance Action Committee (IRAC). [two]