chap 17: ecology Flashcards
define producers
producers are organisms that make their own food e.g. green plants use chlorophyll to convert light energy into chemical potential energy(stored in glucose) and release oxygen as a byproduct
define decomposers
organisms that help to recycle nutrients within an ecosystem by eating dead or decayinh organisms. decomposers obtain energy by breaking down dead organisms. faeces and excretory products. The decomposition process releases inorganic nutrients, such as carbon and nitrogen for nutrient cycling.
why is energy flow non-cyclic?
Energy is lost as heat to the environment, through respiration, as it flows through the ecosystem. Since this heat energy does not return to the same system or to the organisms that produced it, it cannot be recycled in the ecosystem
effects of water pollution by sewage and by inorganic waste?
Sewage water may contain disease-causing organisms such as bacteria which can affect a large number of people w diseases if they get into drinking water (e.g. cholera, typhoid). Untreated sewage and inorganic chemical fertilisers contain phosphates and nitrates which are nutrients for the plant. Excessive use of these fertilisers may result in eutrophication
define eutrophication
eutrophication is the process where water receives excess nutrients like phosphates and nitrates, which cause excessive growth of algae and water plants.
outline the causes and effects of eutrophication
Cause: Untreated sewage/ fertilisers that are not absorbed by crops may be washed by rainwater into nearby rivers and lakes.
Effects:
1. the N&P in ___ enhance the growth of algae and water plants. they are used in the synthesis of proteins and nucleic acids, which leads to the increased growth and multiplication of algae and floating water plants in rivers or lakes.
2. overgrowth of algae and floating water plants prevent sunlight from reaching submerged plants.
3. submerged algae and water plants die due to lack of sunlight. tthey are decomposed by fungi and aerobic bacteria which uses up oxygen
4. bacteria grow and multiply rapidly as they feed on the decaying organic matter, using up exygen rapidly
5. other organisms die due to lack of oxygen
define pollution
pollution is the addition of substancs to the environment that damage it, making it undesirable or unfit for life.
what are the effects of pollution due to insecticides and impact on top carnivores
describe carbon cycle
- photosynthesis
- feeding
- respiration
- decomposition
- combustion
importance of carbon cycle
- ensures that there is a continous supply of CO2 for plants to carry out photosynthesis
- enables energy to flow through the ecosystem. carbon compounds carry the stored energy from organism to organism in the food chains of an ecosystem
- maintains the correct concentration of CO2 in the atmosphere
define carbon sinks
a carbon sink is an area that stores carbon compounds for an indefinite period. it stores more carbon than it releases
outline the role of forests as carbon sinks
atmospheric carboon dioxide is absorbed by plants and used in photosynthesis. in forests, a large amount of carbon compounds is stored in trees. when trees die, their remains may be buried deep in the ground and form coal; a fossil fuel after millions of yeats
outline the role of oceans as carbon sinks
The carbon dioxide that dissolves in the ocean’s water is absorbed and used by phytoplankton and algae in photosynthesis. A portion of the carbon compounds found in oceans is buried in the seabed and is in the form of fossil fuels such as natural gas and oil
outline the roles of microorganisms in sewage treatment as an example of environmental biotechnology
discuss reasons for conservation of species with reference to the maintenance of biodiversity and how this
is done, e.g. management of fisheries and management of timber production
