B6 Flashcards
What is biodiversity
The variety of living organisms in an area
What is species richness
Number of different species in a habitat
What is species eveness
Abundance of each different species in an area
What is genetic diversity
Number of different alleles in a gene pool of one species
What is a quadrat
A large square split into an even number of sections
What is a transect
A fixed path (often a measuring tape) that can have information recorded along
How are transects and quadrats used to collect samples
An example of data these can collect is the area of grass cover.
Lay down the transect and put your quadrat down along it at equal intervals
Count the squares with grass in and record where this was along the transect
The quadrat here is used to measure % of cover but can also be used to count number of species
What is the minimum sample size that should be used when investigating biodiversity
10
How do you estimate the number of species in an area
Take a sample of organisms and tag them
Wait a few days then take another sample at the same time from the same place. See how many have the tags and then:
Use petersons capture recapture
Sample 1 × sample 2 ÷ marked organisms in sample 2
What is a pitfall trap / used for
A small hole with a slight cover that insects fall into
The hole must be deep enough so the animals cannot escape
This allows you to collect samples
What is a pooter / used for
Used to collect samples of insects
Two tubes collected to a container
Place one end of the tube to the insect and the other end in your mouth
Suck on the tube to take the animal into the jar
A filter stops the organism from entering your mouth
What is a fly net
A large net that can be used to pick up flying insects and aquatic organisms
What is a branched key
A key that helps to determine what species an organism is from by answering yes or no questions
(E.g is it a plant
Does it have broad leaves. Narrow leaves)
What is a dichotomous key (numbered)
A key where the correct answer to a question tells you which question to ask next.
Correctly answering these questions will lead you to your organism
Does a large or small population have more genetic diversity
Large - more organisms so bigger gene pool
Small - less organisms → more in breeding → smaller gene pool → less genetic diversity
How does deforestation cause a loss of biodiversity
Cutting down trees destroys the habitat
There is less food and shelter available so animals die + plants
Animals and plants can be killed during deforestation
Rainforests hold 89% of the worlds species
How does agriculture cause loss of biodiversity
Cutting down areas to make room for crops destroys natural habitats
Pesticides used to kill insects reduces food availability for the insects predators
Fertilisers lead to Eutrophication
What is Eutrophication
Surface run off (due to rain) causes fertilisers to be washed into bodies of water
As more useful minerals enter the water an algal bloom happens
(Rapid expanse of algae)
This causes organisms in the bodies of water to die
Why do algal blooms kill organisms
As they cover the surface they prevent any aquatic plants from being able to photosynthesis
This reduces the oxygen concentration in the water, killing fish
Oxygen is also used up by bacterial decomposers breaking down the now dead plants
How does hunting and fishing cause loss of biodiversity
Overfishing leads to fish populations decreasing, and these populations will struggle to recover
Hunting animals also reduces the number of natural predators or prey
Hunting / fishing also causes changes in species richness and evenness
How does global warming affect biodiversity
By heating the earth many enzymes may stop functioning correctly (denature)
What is conservation
Protecting a natural environment to ensure habitats and organisms are not lost
What is ex-situ
(Conservation)
Outside the habitat
What is in-situ
(Conservation)
Within the habitat
What is captive breeding / where and how is it done
Pros and cons
Breeding animals together in places like zoos, in an attempt at increasing the population
Pros
Helps to increases population
Cons
Low population numbers → low gene pool →↑risk of inbreeding
Inbreeding means risk of harmful mutations
Ethical issues (animals have limited spaces)
How do different groups try to prevent inbreeding (captive breeding)
Programmes work together and exchange animals of the same species to reduce the risk of inbreeding
What is wildlife management
A conservation method of limiting human access to certain areas
Trapping invasive species
Controlled grazing + coppicing
What is controlled grazing
Limiting the amount of grazing in certain areas so that plant species have time to recover and grow
What is coppicing
Cutting down trees to their stumps, promoting the growth of tree roots
This gives plants more access to light and promotes shoots growth (↑light ↑ photosynthesis)
So more trees grow
What is an extinct species
Species with no surviving organisms left in the world
How do seed banks help prevent extinction
By safely storing seeds there will always be a seed from that plant species, so they can never go extinct
How are seeds prepared / stored in seed banks
The seeds need to be processed cleaned and x-rayed
They are disinfected to kill bacteria and microorganisms on the seed (reduces rate of decomposition)
They are x-rayed to see if the seed is able to germinate
The seeds are frozen to slow the rate of germination + decomposition
What are indicator species
An organism whose presence or absence is used as a measure of pollution
How are lichens used to monitor air pollution
They are made of fungi and algae (symbiotic mutualism)
Sulfur dioxide in the air causes acid rain which effects lichens
Bushy lichens tolerate low levels of pollution.
Leafy lichens tolerate moderate amounts of pollution.
Crusty lichens tolerate high amounts of pollution.
Where each lichen is found tells you the pollution levels in that area
How is water pollution measured (indicator species)
Stonefly nymph → dragonfly nymph →
Low →→
freshwater shrimp → hoglouse →
Slight Medium
Sludge worm → red tailed maggot
High High