Ecology Flashcards
What is photosynthesis?
Chemical reaction which takes place in leaf
Process in plants in which light energy is trapped by chlorophyll to produce sugars & starch
Endothermic reaction as it must absorb energy to work
What are the word & balanced equations for photosynthesis?
Light
Carbon dioxide + water ——-> Glucose + Oxygen
Chlorophyll
Light 6CO2 + 6H2O ———> C6H12O6 + 6O2
Chlorophyll
Describe the steps of the starch tests & the reason behind doing each step
- Put the leaf in boiling water; kills leaf, stopping further reactions
- Boil leaf in alcohol (use water bath, as alcohol flammable); removes chlorophyll from leaf, and makes colour change with iodine easier to see
- Dip leaf in boiling water again; makes leaf soft & less brittle (alcohol makes leaf rigid)
- Spread leaf on white tile & add iodine; if starch is present iodine will turn yellow/brown to blue/black
How do we make sure the starch test is valid?
Before carrying out investigation, we must destarch plant. This involves leaving plant in darkness for 48 hours. This is necessary to make sure any starch found has been produced during investigation.
What are producers?
They can photosynthesise & produce their own food
What are primary consumers?
Animals that feed on plants
What are secondary consumers?
Animals that eat other animals
What are tertiary consumers?
Animals that feed on secondary consumers
What is energy flow?
The sequence of trapping sun’s energy and then passing it on to other organisms as they feed
What tropic level is a producer?
Level 1
What do the arrows represent in food chain?
Direction of the transfer of energy & what eats what
What is the source energy for every food chain?
The sun
What do plants compete for?
Water
Light
Space
Minerals
What do animals compete for?
Water
Food
Territory
Meat
How do we demonstrate plants competing against each other?
In general, the more seedlings planted in a pot, the smaller the average mass of each seedling.
This is because the seedlings are competing for light, space, minerals and water
What are competitive invasive species? What do they do?
Introduction of new species into areas it isn’t usually found, e.g. grey squirrels from USA to UK
They: out-compete native species, usually causing them harm
Spread rapidly when introduced to region
Are almost always introduced by humans
How can we monitor the environment?
Biotic (living) and abiotic (non-living) factors, which are more important for global warming Abiotic factors: Carbon dioxide levels Size of ice fields Water levels Temperature pH Biotic: Lichens - sensitive plants that can be used to monitor pollution, as they only grow in low pollution areas
What is the definition of biodiversity?
The range of species in a particular area
Why can fertiliser be bad for the environment?
Fertiliser running into waterways cause green algae to grow to excessive levels. When the algae die, bacteria decompose & break them down & use up most of oxygen in water, killing fish and other animals
How be we have better land management?
Reclaim old industrial sites for industry, as this avoids destroying existing habitats to provide land
Use brownfield sites (site of previous housing), for housing, as this prevents having to build on grassland or clearing woodland
How can we protect fish stocks?
Introducing fishing quotas
Fishing bans to allow fish to recover
Restriction on net sizes
What are nature reserves?
Used to improve biodiversity in region by protecting & conserving rare species & valuable or rare habitats
Can be open to public or closed off depending on how fragile habitat is
They can promote biodiversity by educating public
Usually managed by government agencies or charities
