intermediate biology 4

environmental studies: human influences-impact on the environment

wetland

a marsh, swamp, or other area of land where the soil near the surface is saturated or covered with water, especially one that forms a habitat for wildlife

food security

the availability of food and people’s access to it

genetic vigour

relates to the genes which determines an organism’s ability to be stronger, healthier,etc.; to increase this requires back-crossing to the strong wild ancestral strains

monoculture

a form of farming in which large areas of land are planted witha single species of crop ( such as maize or wheat)

explain the 7 steps of eutrophication

Step 1: Eutrophication and algal blooms occur when fertlizers, detergents, sewage, and other nutrient rich organic wastes enter the water.

Step 2: This causes algae and water plants to grow prolifically.

Step 3: The increased plant growth in turn stimulates the population of decomposers such as bacteria which in turn leads to the oxygen being used up in the water.

Step 4: The shortage of oxygen kills fish and other aquatic life.

Step 5: As a result, the amount of anaerobic bacteria increases to decompose all of the dead material.

Step 6: When these anaerobic bacteria die toxins are released which further reduces the quaility of the water.

Step 7: A eutrophic body of water can be recognized by the presence of a thick layer of green pond scum on the surface.

expalin briefly how a septic tank works

A septic tank system traps grease and large solids and discharges the remaining wastes over a large drainage field. As these wastes percolate downwards the soil filters out potential pollutants. The soil bacteria decompose biogradable materials. Septic tanks must be installed in soils with adequate drainage, not placed too close together or near borehole sites and the septic tank must be pumped out regularly when it becomes full.

list 5 ways in which we could conserve water in our everyday lives

1. not leaving taps running unnecessarily

2. mending broken taps and pipes

3. washing cars and areas conservatively

4. showering instead of bathing

5. use water saving devices such as low-flow shower heads, double action toilet flushing systems

why is food insecurity rising?

Food insecurity is rising because of aggravating circumstances, such as the ever-increasing human population, rising food prices, high fuel prices, unemployment, and global economic problems.

scripture for this P.A.C.E

“I am the Lord, and there is no other; There is no God beside Me. I will gird you, though you have not known Me…”- Isaiah 45:5

discuss the four farming practices that may lead to food shortages

1. Where monoculture is practised, crops are at risk of being destroyed by disease or disasters, such as droughts and floods.

2. Overuse of pesticides may cause the pests to become immune to them, as a result the crops getting destroyed by the new resistant pest strains.

3. Soil erosion and topsoil caused by intensive agriculture and intensive over-grazing ffect the growth of the crop and makes the land less suitable from growing foods.

4. Use of synthetic fertilizers which leach ito water bodies and could cause eutrophication.

what arguments will you put forward to lobby against the widespread use of GM food?

GM foods cause allergies in humans, weaken the natural gene composition, animals under-going research are placed under stress, loss in biodiversity, and can be exploited by opportunists.

when and why does wastage of food occur?

Food wastage occurs during the production stage ( generally in low income where poor farming practices cause losses) and in the consumption stage ( in higher income countries where too much food is available and is then wasted).

in what ways do the following affect the availability and quality of water?

exotic or alien plantations: Exotic species consume vast amounts of water daily (200-400 litres). The effect of this is to deprive the natural indigenous vegetation of much needed water.

boreholes: If too much water is pumped out of boreholes , this may cause the water table to drop which could affect boreholes in neighbouring areas; partial underground vacuums may arise due to this and this could cause sinkholes; in coastal areas these may fill up with salt water.

alien

foreign ( to the country or encironment); does not originally come frm there

aquifer

an underground layer of water-bearing permeable rock or gravel, sand or silt from which groundwater can be extracted using a well

bio-indicator

indigenous plants and animals that indicate the presence or absense of pollution in water

effluent

liquid waste discharged from a sewage system, factory, or other industry

leach

when substances drain away from the soil when dissolved in rainwater passing through it

leachate

the liquid that is formed abd drains out of a landfill site

climate change

the alternation of earth's general wether conditions

exploitation

the over use or development of something to gain a bebefit

genetic engineering

when genes are manipulated by selective breeding to produce stronger, healthier varities

thermal pollution

pollution by heat; for example, when hot effluent is released into rivers from factories

carbon sinks

environmental reservoirs where more carbon dioxide is absorbed than released such as forests, the ocean, etc.

eutrophication

a process that occurs in water bodies when the demand for oxygen exceeds the amount of supply; this causes death of aquatic organisms; generally occurs when run-off of nutrient-rich materials such as sewage and fertilizers pollute the water

subsistence farming

farming that generates only enough produce to feed the farmer’s family, with little or nothing left over to sell

genetically modified foods ( GM foods)

foods that are produced by genetic enginerring

“sixth extinction”

the large-scale destruction of natural habitats leading to global mass extinction

poaching

1. the illegal capture and trade of wildlife and indigenous plants

2. to catch wild animals or fish illegally on public land or while trespassing on private land

indigenous knowledge

information which is passed on from one generation to another regarding the use of useful plants growing naturally in certain areas

nuclear waste

material that is radioactive and decomposes over time measured from minutes to thousands of years

methane

1. a gas produced by the fermentation and decomposition of organic materials

2. the gas that is collected from land fill sites and is converted into electricity

carbon footprint

a measure or unit of the amount of carbon dioxide ( and other “greenhouse” gases) caused by human activity and the effect on the environment

desertification

increasing dryness of the land causing vegetation to fail and deserts to form

global warming

the increase in the average temperatures around the world which some scientists say is due to the rising levels of the so-called “greenhouse gases”

chlorofluorocarbons ( CFCs)

organic compounds containing chlorine, fluorinem and carbon; were previously used in refrigeration

deforestation

a form of land degradation in which large areas of trees are chopped down causing damage to the environment

Kyoto Protocol

an international agreement to try to get nations to reduce on their emissions of greenhouse gases

biome

an area of vegetation that corresponds to a particular climae and is characterized by specific types of plants and animals, e.g. tropical rainforest or desert

IUCN

International Union for the Conservation of Nature

greenhouse effect

an effect in which the infrared radiation of the sun tends to be trapped by carbon dioxide, water vapour, and other gases in the earth’s atmoshpere and some of it is re-radiated back to the earth’s atmosphere, causing it to heated

ozone depletion

a decrease in total volume of ozone in the atmosphere

hydrofluorocarbons ( HFCs)

organic compounds that contain hydrogen, fluorine, and carbon

4 waste from mines

1. arsenic

2. coblat

3. chromium

4. asbestos

3 wastes from domestic households

1. detergents

2. toiletries

3. pesticides

4 wastes from industries

1. salts

2. chlorides

3. strong acids

4. bases

5 activities of man that can have a negative impact on the environment

1. burning or combustion of fossil fuels

2. poor farmimg methods

3. deforestation

4. desertification

5. industrialization

the 5 main greenhouse gases

1. carbon dioxide

2. methane

3. CFCs

4. nitrous oxide

5. ozone

explain the greenhouse effect

Solar energy ( also referred to as infrared energy or radiation from the sun) strikes the earth in short waves. Short waves make it easier for this energy to pass through the atmosphere. Much of the energy that strikes the earth is reflected back to the atmosphere, and beyond as long waves. Long waves do not pass through the atmosphere easily, so some is reflected back to the earth. Certain gases, the so-called “greenhouse gases,” such as CO2, absorb some of the reflected long infrared waves of solar energy and re-emit it downwards to the earth. In other ways, they trap heat and prevent it from radiating back into the atmosphere.

how is the greenhouse effect a problem to animals

the greenhouse effect may cause climate change ( droughts and floods) which could have detrimental effects on the availability of their food and water in their natural habitats which may cause the animals to die out or they may have to move away into other areas.

essay: acid rain

Acid rain is any type of precipitation which is polluted with acids such as sulphuric acid and nitric acid. When petrol, coil, or oil is burned, they emit waste products of sulphur dioxide, nitrous oxide, or nitrogen dioxide gases in the atmosphere. The longer they stay in the air the more chance of there is of them combining with water vapour to form sulphuric acid and nitric acid. It is these acids which fall to the ground as acid rain.The effect of acid rain are to harm ecosystems by polluting water bodies and killing aquatic life, trees and other plant life are killed or their growth is adversely affected. Acid rain can be prevented by preventing or reducing the burning of fossil fuels and the emission of toxic gases into the air and using alternative sources of fossil fuels.

essay: ozone depletion

The ozone layer can ne damged by high energy molecules such as chlorofluorocarbons (CFCs) and hydrofluorocarbons ( HFCs). Ozone in the stratosphere absorbs ultraviolet (UV) from the sun before it hits the earth. Without the ozone layer, the harmful UV rays could have detrimental effects on humans, animals, and plants. Ozone at the ground level is a poisonous gas and and pollutant that helps from photochemical smog and acid rain.

name the 8 harmful effects of UV radiation

1. can destroy DNA

2. can cause mutations in the DNA of all life

3. can cause sunburn, eye damage, skin cancer, skin wrinkles, caracts

4. can weaken immune systems

5. can prevent plant seeds from germinating

6. damages plant life

7. kills off algae in both fresh water and in the ocean

8. a decrease in the algae means that the primary producers will be affected by having less food available. this will cause an imbalance in the food chain

list the 10 ways an individual could reduce their carbon footprint

1. insulate buildings to decrease energy loss

2. use energy-efficient vehicles

3. use more energy-efficient electrical appliances

4. use natural products

5. switch off lights and electronic devices when not in use

6. use more renewable sources of energy

7. plant more indigenous trees

8. reduce on packaging

9. recycle or reuse paper, plastic, and glass

10. do waste water

what 3 things destroy natural habitats that result in the loss of species?

1. poor farming methods

2. deforestation

3. loss of wetlands and grasslands

what does the use of recycled water do?

the use of recycled water on golf estates adds nutrients to the surrounding ecosystems which leads to eutrophication of water bodies

discuss the detrimental effects of alien plant invaders on the indigenous vegetation

1. Alien plants usually grow faster than indigenous plants, an withstand drouhgts and have few natural enemies

2. They comsume vast amounts of water, leaving little to nothing left over from indigenous plants to use.

3. They replace indigeous plants and reduce biodiversity.

4. Even after they are removed, their effect on the soil pH, nutrient and water cycle may be prevent indigeoud plants from being established again

5. They cause the degradation of vegetation and loss of farmland because they need to be continuously removed to regain the farming land.

3 gradual changes caused by human activites

1. pollution

2. over-fishing

3. harvesting endangered species

what 3 things are directly proportional to the accumulation of waste?

1. the increasing size of the population

2. consumerism

3. man’s irresponsibility

landfills sites are…. what 3 things?

1. often not well built nor well maintained

2. may be built mear human settlements whick pose health risks

3. become home to carriers of diseases such as flies, rats, and mice

the process of converting methane gas into electricity happens as follow:

solid waste is compacted and fermented; gas is collected in wells; piped to main gas collector; spark ignition generators convert the gas into electricity

why is nuclear waste dangerous?

it is radioactive and harmful to all life

what are the 3 kinds of nuclear waste

1. LLW: low-level waste

2. ILW: intermediate-level waste

3. HLW: high-level waste

essay: carbon dioxide emissions

The burning or combustion of fossil fuels, deforestation, decomposition, and respiration all add more carbon dioxide into the atmosphere. The countries with the highest CO2 emissions are China, the USA, EU countries, India, the Russian Federation, and Japan. However, the Kyoto Protocol is an international agreement to try and get countries to reduce their carbon emissions. This could help reduce these emissions.

3 ways to reduce personal waste

1. avoid buying products that have a lot of extranous packaging

2. use only productd that can be reused, refilled and/or repairable

3. collect recycling items and take them to recycling depots or collection points. items that can be recycled or reworked include paper, glass, plastic, etc.

essay: greenhouse gases with specific reference to carbon dioxide

Carbon dioxide, methane, nitrous oxide, CFCs, and ozone are all greenhouse gases. They prevent heat from radiating back into the atmosphere. Carbon dioxide accounts from almost half of all global greenhouse gases. Activities such as the burning or combustion of fossil fuels, decomposition, deforestation, and respiration all release carbon dioxide into the atmosphere. Carbon dioxide is naturally predent in the atmosphere as a part of the earth's carbon cycle. The amount of carbon dioxide in the atmosphere has increased since the Industrial Revolution.

effect: the greenhouse effect and global warming

Due to the greenhouse effect, certain gases, the so-called “greenhouse” gases, such as CO2, absorb some of the reflect long infra-red waves of solar energy and re-emit it downwards to the earth. This generally provides a comfortable temperature for life on earth to flourish. Global warming is an enhanced greenhouse effect, which according to some scientists is being made worse by the activities of humans due to industrialisation (using fossil fuels) and deforestation.

essay: deforestation and desertification

Deforestation is a form of land degradation in which large areas of trees are chopped down, causing harm to the environment. Trees and other plants absorb CO2 in their tissues during the process of photosynthesis and they help maintain an efficient carbon cycle. Forests are carbon sinks, so cutting down forests results in an increase of CO2 in the atmosphere. Deforestation accounts for 20% of all global greenhouse emissions. Desertification is an increasing dryness of the land causing vegeation to fail and deserts to form. It is caused by overgrazing, incorrest land use, and decreased annual rainfall. Its consequences are accelerated soil erosion by wind and water, reduced water cycle efficiency, loss in soil nutrients, increased flood damage and a decrease in biodiversity. When forests are destroyed by the removal of trees and lands turned into deserts, the effect is to reduce natural carbon sinks which would be removing CO2 from the atmosphere for photosynthesis.

essay: an alternative viewpoint to causes of climate change

Carbon dioxide is not a pollutant. Other gases, such as sulphuric acids, that are released from the burning of fossil fuels are more harmful to humans. Higher carbon dioxide levels actually improve plant growth and productivity. Global warming does not necessarily mean that the tropics will be hotter. Melting permafrost will not drown the continents. Global warming is not making the weather more violent. Climate change is not caused by human activity alone. CClimate chnge is caused by solar activity which regulates cloud formation, includes heat, solar wind, and sunspots.

essay: droughts and floods

Rainfall patterns are predicted to change because the air pressure changes induced by the rise in temperatures on land and increase in ocean temperatures. This will affect the frequency or not of rain. Droughts and floods have increased since the 1970s in different regions.

essay: methane emissions

Methane (CH₄) is produced by the fermentation of organic molecules such as rotting vegetation in wetlands and forests and in dumpsites; from melting permafrost and decomposing animal wastes; from rice paddies (water logged soil) and from burning organic waste. Many industry processes, mining, sewage works, and gas distribution systems also produced methane.

essay: carbon footprint

A carbon footprint is a measure or unit of the amount of carbon dioxide (and other “greenhouse” gases) caused by human activity and the effect on the environment. It can be reduced by using …:

1. insulated building for energy conservation

2.energy-efficient vehicles

3. energy-efficient electrical appliances

4. natural products

5. more renewable sources of energy

6. switching off lights when not in use

7. planting more indigenous trees

8.not wasting water

9. recycling or reusing paper, plastic, and glass