Environment and Evolution Flashcards
How does waste impact water?
Sewage and chemicals are released into it causing eutrophication
How does waste impact land?
Toxic chemicals can get washed into water. Nuclear waste is also buried underground and household waste in landfill sites
How does waste impact the air?
Smoke and gases pollute the air
What 4 main activities reduce the amount of land available for farming and other animals?
Building, farming, dumping waste and quarrying
Describe the stages of eutrophication
Mineral ions enter water causing algae to grow fast
Algae covers top of water blocking sunlight which causes plants to die and a microorganism increase
Respiration of microorganisms depletes oxygen causing fish to die
What is deforestation?
Chopping down trees
Why is there deforestation?
Clear land for farming, provide more food, grow crops
What problems are caused by deforestation?
More methane in atmosphere
More CO2 in atmosphere
Less CO2 taken in
Less biodiversity
Why is the destruction and drainage of peat bogs bad?
CO2 is released into the air
How are peat bogs formed?
The plants in bogs don’t fully decompose due to lack of O2 which forms peat
What are some ways carbon dioxide can be sequestered?
Oceans and lakes, peat bogs, green plants
What are the 2 main greenhouse gases?
Methane and carbon dioxide
What are the consequences of global warming?
Rising sea levels, ice melting, extreme climates, distribution of flora and fauna will change, reduced biodiversity in affected areas, changes in migration patterns
What is the theory of evolution?
More than 3 billion years ago, life on earth began as simple organisms from which more complex ones evolved
Are ALL organisms related?
Yes
Why do similar species have similar genes?
Because they share a recent common ancestor
Why was Darwin’s theory of evolution only slowly accepted?
Went against religious beliefs, wasn’t a good explanation as to why new characteristics were developed, wasn’t enough evidence
What was Lamarck’s theory?
If an animal used a characteristic a lot, it would become more developed
What are fossils?
Remains of flora and fauna
What are the 3 ways fossils can form in rocks?
From gradual replacement by minerals, casts and impressions and preservation
How are fossils formed by gradual replacement by minerals?
Bones etc are replaced by minerals as they decay forming rock-like substances
How are fossils formed by casts and impressions?
When an organism is buried in something like clay, the clay hardens around it forming an impression
How are fossils formed by preservation?
In places where no decay happens, the decay microbes don’t work allowing preservation
Why does extinction happen?
Because an organism can’t evolve quickly enough
Name some reasons as to why species become extinct
Environment changes quickly, new predator, new disease, can’t compete, catastrophic event, new species develops
What is speciation?
The development of a new species
When does speciation occur?
When populations of the same species become so different they can no longer breed together to produce fertile offspring
What are causes for speciation?
Isolation and natural selection
Describe what happens in natural selection of a population which has recently been isolated
Genetic variation due to wide range of alleles, survival of the fittest allows successful genes to be passed on, alleles which control beneficial characteristics are more likely to be passed on
What is biomass?
The mass of living material
How can the efficiency of food production be improved?
Reduce number of stages in food chain
Restricting energy loss by farm animals
How can you restrict energy loss by farm animals?
Battery farming
What are some arguments against factory/battery farming?
Cruel -> Growing demand for organic food
Crowded conditions make disease spread faster
Antibiotic immunity in animal
Fossil fuels used to keep animal warm
How are elements cycled back to the start of the food chain?
By decay
What conditions make decay faster?
Warmer, moist and aerobic conditions
What factors contribute to CO2 in the air?
Burning, plant and animal respiration, decay
