Ecosystems, nutrient cycles and human impact on the enviornment Flashcards
(37 cards)
Why is the increasing population causing effects on the environment?
- More space needed for housing
- Agriculture
- Industry
What does intensive farming mean?
Using chemicals on crops and keeping animals in cages/small spaces in order to increase the yield of crops produced.
What are the advantages and disadvantages of fertilisers?
Advantages - increases crop yield by making crops grow faster and bigger
Disadvantages - Can result in chemicals being washed from soil to waterways
What are the advantages and disadvantages of pesticides?
Advantages - stops insects eating crops
Disadvantages - kills useful insects like bees which pollinate
What are the advantages and disadvantages of Disease control?
Advantages - Prevents death of plants and animals to disease
Disadvantages - could lead to antibiotics being present in meat and animals becoming resistant to antibiotics
What are the advantages and disadvantages of battery methods?
Advantages - animals waste less energy and food can be controlled
Disadvantages - animals are not treated fairly and has an impact on the welfare
What are indicator species?
Living things that tell us about the level of pollution in air or water
How can air pollution be detected using living organisms?
Air pollution can be detected by lichens, which are damaged by sulphur dioxide from burning fossil fuels—fewer lichens indicate more pollution.
How can water pollution be detected using living organisms?
Water pollution is indicated by changes in pH and oxygen levels, and the absence of sensitive aquatic invertebrates shows higher pollution levels.
When does Bioaccumulation occur?
when pesticides or heavy metals enter the food chain
How do harmful chemicals like pesticides and heavy metals affect food chains?
These chemicals enter the food chain through producers and accumulate at each trophic level because they aren’t easily broken down. By the time they reach top predators, the concentration can be toxic, leading to reduced fertility or death.
What is leeching
Untreated sewage and fertilisers may run into waterways
What leads to an algal bloom?
Untreated sewage and fertilisers cause rapid growth of plants and algae.
What does algal bloom cause?
Blockage of sunlight from reaching plants, killing them and are then decomposed by bacteria. The bacteria increase in number and use up dissolved oxygen in the water for respiration, animals that live in the water may suffocate due to lack of oxygen
What does a food chain show?
The transfer of energy between organisms
What do the arrows in a food chain show?
The flow of energy
What is a source of energy for most organisms?
Radiation from the sun
What do green plants capture?
A small percentage of this solar energy during photosynthesis
What is a producer?
The green plant that makes its own food during photosynthesis, using light energy from the sun
What is a first stage consumer?
An animal that eats the producer, this is a herbivore
What is a second stage consumer?
An animal that eats the first stage consumer, this is a predator
What is a third stage consumer?
An animal that eats the second stage consumer
What is a decomposer?
An organism that breaks down dead or waste materials and releases nutrients
What decreases as you move along the food chain?
The number of ‘units’ due to energy being used and lost at each stage of the food chain
