Concept explainers
CASE STUDY| Fish tales
Aquatic vegetation overgrowth, usually controlled by dredging or herbicides, represents a significant issue in maintaining private and public waterways. In 1963, diploid grass carp were introduced in Arkansas to consume vegetation, but they reproduced prodigiously and spread to eventually become a hazard to aquatic ecosystems in 35 states. In the 1980s, many states adopted triploid grass carp as an alternative because of their high, but not absolute, sterility and their longevity of seven to ten years. Today, most states require permits for vegetation control by triploid carp, requiring their containment in the body of water to which they are introduced. Genetic modifications of organisms to achieve specific outcomes willcertainly become more common in the future and raise several interesting questions.
Taking triploid carp as an example, what controversies may emerge as similar modified species become available for widespread use?
To review:
The controversies that emerge from using modified species available for widespread use, keeping in mind the case of triploid grass carp.
Introduction:
There exist aquatic weeds which is harmful to the survival of other species. Grass carp are genetically modified so that it could wipe away the population of these weeds. These genetically modified organisms (GMOs) are made to be survived for a longer time, for about a period of five to ten years.
Explanation of Solution
Grass carp is a genetically modified fish which is used for controlling aquatic weed but there are also few controversies associated with their use-
1) Incorrect insertion of the gene of interest- During the insertion of the gene of interest, there might occur some undesirable changes in the functionality of organism as while creating triploid grass carp, they may harm aquatic vegetation without disrupting the weed population.
2) Harmful to the environment- Due to gene insertion, the modified organism may start producing toxic substances and releasing it in the environment, affecting the environment negatively. For example- some portion of weed eaten by modified grass carp may not be completely digested and excreted to further cause algal blooms.
3) Resistance by pests and weeds towards the GMOs:A prolonged use of genetically modified organisms against insects, pests or weeds, may cause the development of resistance in these organisms against the GMOs. Hence, the GMOs should be used carefully against other organisms.
4) Disruption to biodiversity and vegetation: If a wide population of a particular species is wiped out then this would disrupt the biodiversity and vegetation of that place. For example- if triploid grass carp starts eating the useful aquatic vegetation along with the weeds then this will pose a harmful impact on the aquatic environment.
5) Harmful to human health- In some cases, GMOs have shown to leave behind toxic substances which cannot be degraded when such substances contaminate a region then it may be later consumed by humans which would result in serious health problems.
Thus, it can be concluded that GMOs are effective and necessary to be used in the modern world but it also has certain drawbacks.
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Chapter 6 Solutions
ESSENTIALS OF GENETICS-MODIFIED ACCESS