second exam (ecosystem)

• Matter cycle is when different kinds of matter are transferred around the ecosystem
• Nitrogen cycle in nitrogen in the atmosphere is used by living organisms, and released back into air and soil.
• Nitrogen is used in DNA, RNA, ATP and chlorophyll.
• Nitrogen is found freely in the air, but plants and animals can't use this nitrogen.
• Nitrogen is converted into NH4 and NO3 by bacteria living ın the roots of legumes. This is called Nitrogen fixation. Bacteria are living organisms, so this is a biotic progress.
• Nitrogen can also be transferred from air into soil by lightning. This is an abiotic progress.
• Plants use nitrogen to make organic matter such as ammonium. Herbivores eat plants and get ammonium into their body. So, nitrogen is transferred from plants to animals.
• Artificial fertilizers also increase nitrogen in the soil.
• Factories release nitrogen gas into the air
• Decomposers feed on dead animals and plants and release ammonia (NH3) into soil.
• Nitrifying Bacteria in soil convert ammonia into Nitrite and then Nitrate. Nitrates are then taken by plant roots.
• Denitrifying Bacteria in soil break down nitrate and nitrate into Nitrogen. Nitrogen gas is then released into air. Denitrified soil becomes less productive.
• Carbon is one of the elements found in living organisms.
• Photosynthetic organisms like plants take up CO2 ( carbon dioxide ) from the atmosphere and use it to form carbohydrates.
• Consumers and Decomposers take up organic carbon from other organisms. Then, they lose carbon to the atmosphere in the form of CO2 during respiration.
• Some dead organisms stay under the ground for many years and form Fossil Fuels such as petrol and coal
• Human industry burns these fossil fuels in factories and release carbon back into the atmosphere during the combustion.
• Destruction of the ecosystem by the effects of chemical pollutants is called environmental pollution
• main environmental problems include; air pollution, global climate change, erosion, destruction of natural habitats and loss of biodiversity.
• Air consist of gases nitrogen, oxygen, argon, carbondioxide and water vapour.
• Increase of the pollutant gases in the air causes air pollution.
• These gases are SO2 (Sulphur dioxide), CO2 (Carbon dioxide), O3 (ozone) and NO2(nitrogen dioxide), CH4 (methane), CFC (chlorofluorocarbons).
• Volcanic eruptions, wildfires, sand storms are natural causes of air pollution.
• Thermal reactors, factories, oil refineries are human-made pollutants.
• Air pollution causes destruction of nature, harms human life, increases Greenhouse effect and damages the ozone layer.
• Increase of pollutant in surface and ground waters is called water pollution.
• Chemicals from factories, Detergents and bleach from houses, Oils and Sewage cause water, dense such as Mercury and lead and agricultural Fertilizers cause water pollution.
• Eutrophication is the excessive plant and algal growth due to increased amount of nutrients.
• When the water becomes rich of nitrogen and phosphorus, numbers of Algae and photosynthetic bacteria start to increase. These microorganisms will eventually die and decomposers will start feeding on them, which leads to depletion of all Oxygen in water. Water becomes Anoxic and fish start to die. There will be a bad smell too
• These polluted waters can cause Cholera, Typho or Dysentery illness in humans
• Deterioration of the physical and chemical structure of soil is called Soil Pollution.
• Mercury, cadmium, lead or heavy metals which pollute soil. Heavy metals lead to Biomagnification (bioaccumulation) in living organisms. They also can cause Cancer, nervous diseases, respiratory illness, liver and kidney disorders.
• Wrong use of fertilizers also cause soil pollution.
• Radioactive materials pile up in the environment and the body of living things.
• Most common sources of radiation are nuclear reactors, X-ray, MR, mobile phones, TV, microwave ovens and batteries.
• Radioactivity causes cancer, mutations, radiation burns, genetic disorders and immune disorders.
• Radiation from mobile phones is known to cause nervous system diseases like Alzheimer's, Parkinson and MS.
• Sounds above a certain decibel threshold are defines as noise
• Noise pollution can cause loss of hearing, respiratory disorders and cardiovascular disease.
• It also causes psychological problems such as stress, ADHD and insomnia.