Answer: In the wetland, nitrates are absorbed by plants or converted (through an anaerobic process called denitrification) to nitrogen gas and lost to the atmosphere. Nitrate-N is efficiently removed from wetland surface waters by aquatic plants. Ammonium-N enters wetlands primarily through surface runoff.
Nitrogen pollution in wetlands is processed through the nitrogen cycle involving ammonification, nitrification, and denitrification, conducted by various bacteria and fungi. These processes recycle nitrogenous waste and send it back to the atmosphere, the ocean floor, or the terrestrial food web as organic nitrogen.
Nitrogen pollution, resultant from human activities like burning of fossil fuels and use of artificial fertilizers, can be processed by wetlands through a biological process known as the nitrogen cycle. The cycle involves three steps: ammonification, nitrification, and denitrification. In the ammonification process, nitrogenous waste is converted into ammonia (NH3) by bacteria and fungi. This ammonia is then oxidized to nitrite (NO₂), and then to nitrate (NO3) in the nitrification process by soil bacteria such as Nitrosomonas. Finally, in the process of denitrification, soil bacteria like Pseudomonas and Clostridium, convert nitrate into nitrogen gas that reenters the atmosphere. Some of this nitrogen also settles into the ocean floor as sediment and becomes incorporated into terrestrial rock. Nitrogen thus processed by the wetland becomes the organic nitrogen required by the terrestrial food web.
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Melanism related to the process of adaptation is called adaptive. Most commonly, dark individuals become fitter to survive and reproduce in their environment as they are better camouflaged. This makes some species less conspicuous to predators, while others, such as black panthers, use it as a foraging advantage during night hunting.Typically, adaptive melanism is heritable: A dominant gene, which is entirely or nearly entirely expressed in the phenotype, is responsible for the excessive amount of melanin.
Adaptive melanism has been shown to occur in a variety of animals, including mammals such as squirrels, many felines and canids, and coral snakes. Adaptive melanism can lead to the creation of morphs, the most notable example being the peppered moth, whose evolutionary history in the United Kingdom is offered as a classic instructional tool for teaching the principles of natural selection.
Answer:
C
Explanation:
In the Igf-2 allele, which chromosome is imprinted? Which is expressed?
Match the following terms with their descriptions below.
If a cell is fused with another cell, which of the following would be the best example of a trans-mechanism of epigenetic control?
Answer: A gene that is originally silenced in one cell but expressed in the other is silenced in the hybrid.
I hope this helps, Regards.
The trans-mechanism of epigenetic control can result from the fusion of cells, as seen when certain diets in mice alter DNA methylation. An example of gene imprinting, another form of epigenetic control, is seen in the Igf-2 allele where the paternal allele is expressed and the maternal allele is silent.
The fusion of cells can lead to a specific type of epigenetic control, termed trans-mechanism. This process is best exemplified in the case of the pseudoagouti offspring phenomenon in mice. When female mice are fed a specific diet, it alters the methylation processes of their DNA. As a result, a specific region in the agouti gene becomes hypermethylated which in turn leads to an increased proportion of pseudoagouti offspring.
Addressing the second part of your question, in the Igf-2, or the Insulin-like growth factor 2 gene, it is the paternal allele that is usually expressed while the maternal allele is imprinted and silenced. Imprinting is another form of epigenetic control where the activity of a gene is determined based on which parent the allele was inherited from.
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Answer:
mutualism
Explanation:
Mutualism is a type of symbiotic relationship between two organisms in which both benefit and neither is affected negatively in any way.
Mutualism can be in the form of resource-resource when it involves an exchange of resources between the organisms, service-resource when a resource is being swapped for a service or, service to service when it involves exchange of services between the two organisms.
In this case, the clownfish offers protection service to the sea anemone while the sea anemone in turn also offers protection to the clownfish. This is a service-service mutualism.