Understanding Soil Contamination and Its Environmental Impact
7. He cites the main causes of soil contamination.
Nitric acid and sulfuric acid from acid rain; pesticides and fertilizers from intensive agriculture; municipal waste; industrial waste; health waste from mining; and acid water with heavy metals from sulfur mineralization.
What are the causes of eutrophication?
Eutrophication is produced as a consequence of the discharge of sewage from urban centers (rich in organic remains) or fertilizers that come from intensive agriculture.
Describe what would happen in a stream when it receives a discharge of sewage.
The water turns into a smelly mass covered with several green colonies, which kills the entire ecosystem, being replaced by undesirable creatures that can survive in low oxygen concentrations, such as larvae and mosquitoes.
What is a black tide? What are the consequences for aquatic flora and fauna?
A black tide is a layer of oil floating on the water, hindering the entrance of light and water oxygenation, which leads to the death of many organisms. The flora and fauna most affected are those that live closest to the surface, which are part of indirect trophic chains, leading to alterations in these food chains.
8. Why are harmful plastics that are thrown uncontrollably?
They remain floating for a long time and are ingested by various marine animals, causing gastrointestinal obstruction and death. 9. Define biodiversity and list the main causes of its disappearance.
Biodiversity is the variety of species known in an ecosystem.
– Loss of natural habitats
– Excessive pressure on resources
– Introduction of exotic species
– Water contamination
– Soil and atmospheric pollution
– Use of poisoned baits.
Explain the basis of the rule of the three Rs.
The rule is to apply the three Rs: reduce, reuse, and recycle to try to lessen the problem posed by waste.
To reduce waste, it is necessary to implement cleaner technologies that produce less waste. It is also essential to curb the consumerist desire by avoiding unnecessary purchases of products that quickly become garbage and avoiding products with excessive packaging.
Reuse means using a product again before discarding it. For example, using pages written on one side to make sketches or proofs on the other, or using returnable glass bottles (which are washed and sterilized for refilling).
Recycling involves using discarded materials to manufacture new products rather than using raw materials. For example, discarded paper in blue containers is used to make new paper instead of cutting down trees.
7. Explain what type of containers is advisable to use: non-returnable or refundable.
Returnable containers should be used, as they are not thrown away (i.e., reducing waste) but are reused (washed and sanitized) to be filled again. This, in addition to reducing waste, saves raw materials.
A major environmental problem is the existence of uncontrolled landfills where people throw their waste without any control. Explain how environmental problems can arise from these landfills. Waste contaminates soil and surface water and groundwater. Wildfires can occur, causing further damage. They attract pests like rats and seagulls, leading to epidemics. They also cause discomfort and unpleasant odors in surrounding communities.
8. Indicate the main advantages and disadvantages of waste incineration.
Advantages: reduces the volume of waste and therefore requires less space for storage.
Disadvantages: it produces gases and ash contaminants (dioxins from the incineration of plastics are among the most toxic chemicals known). It is also an expensive process. 9. Define sustainable development. Sustainable development is the model of development that meets the needs of the present without compromising the ability of future generations to meet their own needs.
CELL QUIZ
1. Indicate what the tenets of the Cell Theory are:
All living beings consist of one or more cells.
Living cells are the simplest and smallest units of life.
All cells arise from other existing cells.
Each of the cells that constitute a multicellular organism has its own activity, although there is coordination between them.
2. Why do we say that the cell is the structural unit of all living things? Why is it the functional unit of all living things?
Because all living beings are composed of cells, which are the basic units of life and conduct the three vital functions.
3. What is the purpose of cellular nutrition? To take molecules from the external environment (nutrients) and transform them into energy to carry out their functions or into their own molecules, in order to renew cellular structures and dispose of waste.
4. What is called metabolism?
The set of transformations that take place within the cell and form the basis of cellular life.
5. What is the process of cellular communication?
It allows cells to communicate with the external environment, enabling them to adapt to changes and maintain stability. If this function fails, cells cannot survive because they would not be capable of triggering the necessary mechanisms to maintain vital activity. This function has two phases: the first is the receipt of information, and the second is responding appropriately.