Human influences on the Environment Flashcards
What are the biological consequences of pollution of air by sulfur dioxide and by carbon monoxide?
Sulfur dioxide: combines with rainwater in clouds to from acid rain. This acid rain leads to the acidification of the soil which leeches some ions into the lakes which kills fish and makes the root hairs less effective at absorbing minerals so slowing down tree growth. It also causes the acidification of lakes which leads to the death of bacteria, algae, fish and amphibian eggs.
Carbon monoxide: If a person inhales carbon monoxide for a period of time, more and more haemoglobin becomes bound to CO and so cannot bind with oxygen. The person may lose consciousness as the blood carries less oxygen and may die.
Name some of the greenhouse gases
Carbon dioxide, carbon monoxide, sulfur dioxide, nitrogen oxides, methane and CFC’s
How have human activities contribute to greenhouse gases?
The burning of fossil fuels releases carbon dioxide into the atmosphere. The cutting down of large areas of forests means that less carbon dioxide is being absorbed.
How can an increase in greenhouse gases result in an enhanced greenhouse effect?
Short wave radiation from the sun strikes the planet. Some of it is absorbed and some is re-emitted as longer wave radiation. The greenhouse gases absorb then re-emit this longer wave radiation back towards the earth, which would otherwise escape into space. This greenhouse effect causes global warming which melts the polar ice caps, a change in the ocean currents - warm water being redirected to cooler areas and species could be extinct if they cannot migrate to another appropriate habitat.
What are the biological consequences of pollution of water? (Paper 2)
Sewage is Rich in Minerals and Nutrients that Provides Large Amounts of Energy to Allow Organisms such as Decomposers to Reproduce, increasing their Population
Sewage is Rich in Nutrients (Phosphates) that will Encourage the Growth of Algae, causing Algae Bloom to Form on the Surface
Decomposers will Respire Aerobically to Break Down Sewage and Dead Plants (From Lack of Sunlight Due to Algae Bloom) so will cause Depletion of Oxygen, causing Aquatic Organisms to Die
Sewage May Contain Bacteria that will Respire Aerobically, Using Up Oxygen in the Water
Sewage will Increase Population of Organisms in the Water so will cause More Aerobic Respiration to take place, Further Increasing the Depletion of Oxygen
Describe eutrophication
As nitrates levels rise, algae reproduces rapidly. They use the nitrates to make proteins for growth. The algae form an algae bloom which then prevents light from penetrating further into the water so submerged plants cannot photosynthesise and so die. The algae also die as they run out of nutrients. This causes bacteria to decay the dead plants and algae releasing more nitrates allowing the cycle to start again. The bacteria reproduce due to large amount of dead matter and their respiration uses ip more and more oxygen so the water may become totally anoxic and all aquatic life forms will die.
What are the effects of deforestation?
The soil lacks a protective canopy, and is not held together by tree roots so soil erosion
