Ecology Flashcards
What are the two ways of sampling? (SO E Bi)
- random sampling
- sampling along a transect
What is random sampling used for? (SO E Bi)
to compare the numbers of organisms in different areas.
How do you do random sampling with a quadrat and what is the technique used for? (SO E Bi)
place it randomly on the ground and count the number of organisms inside the quadrat. Do this a large number of times to make it more likey that we get valid results. This techniwue is used to sample plants or slow moving animals
What is a quadrat and how do you use it? (SO E Bi)
a wooden or plastic square used in random sampling.
place it on the ground and count the number of organisms inside the quadrat.
How do we use random sampling to estimate the total population size of a species in an area? (SO E Bi)
Use this equation:
total poulation size =( total area / area sampled ) x number of organisms of that species counted in sample
Why is it important that we place a quadrat a large number of times? (SO E Bi)
to make it more likely that we get valid results. If we place it only once that it might not give us a sample which accuratly represents the whole area.
When do we use sampling along a transect? (SO E Bi)
when we want to ivestigate wether the numbers of species change as we move across a habitat
What is a transect and where do we place it when doing sampling? (SO E Bi)
a line such as a tape measure or a piece of rope. We place the transect so it runs across the habitat that we are investigating
How do you do transect sampling? (SO E Bi)
- place the transect across the habitat
- place qudrats at intervals on the transect
- count the number of organisms in these transects
- repeat this a number of times so that we get valid results - move the transect across
What size of quadrat do we use for estimating the total population of daisies? (RP9 E Bi)
0.5m x 0.5m
What is the method for the required practical of estimating the total polulation of diasies? (RP9 E Bi)
Use random sampling
1. Place two tapemeasures at right angles (20m in length)
2. Have two bags which each have numbers 1 to 20 in
3. 1 takes a number from the bag e.g 8. They then move to the 8m point on one of the tape measures
4. 2 takes a number from the bag and moves to that point on the other tape measure. e.g 12
5. 3 takes a quadrat (0.5m x 0.5m) and places it on the ground at the 8m by 12m point
6. record the number of daisies in the first quadrat
7. place the numebrs back into the bag
8. rpeat this process nine more times for a total of 10 samples
9. work out the estimated total population size.
What should you do in the sampling daisies rp when you think that there are large amount that have too many or too little daisies and don’t represent the whole field? (RP9 E Bi)
increase the number of samples that you do so that you can cover a greater percentage of the area
How do you find out how light intensisty affects the number of diasies in an area and what do we expect to come from this experiment? (RP9 E Bi)
transect sampling.
One end of the tape measure should be under a shady part and then it should stretch into the sunny parts
1. record the number of diasies and the light intesisty (ap or light meter) at the shadiest end of the tape measure
2. move the quadrat 1m down the tape measure and repeat the measurements
3. continue all the way down the tape measure
We are likely to find that there is a larger amount of dasisies as we move away from the tree. Because there will be a lower light intensity and plants need light to photosynthesise. Also the tree will absorb a lot of the water and minerals from the soil so light intensity might not be the only abiotic factor affecting the number of daisies
What does every food chain start with? (FCPPC E Bi)
A producer. which is usually a green plant.
Why are producers extremely important in food chains? (FCPPC E Bi)
they synthesise complex molecules which are passed through the food chain. Green plants make the molecule glucose by photosynthesis by using energy from the sun
they are the sources of all biomass in a community
What are molecules such as glucose called? (FCPPC E Bi)
biomass
What are the organisms that eat the producers called? (FCPPC E Bi)
primary consumer
What is a secondary consumer? (FCPPC E Bi)
an animal that eats a primary consumer
What is a tertiary consumer? (FCPPC E Bi)
An animal that eats a secondary consumer
What are consumers that kill and eat other animals called? (FCPPC E Bi)
predators
What is an animal that is being eaten called? (FCPPC E Bi)
prey
What do the numbers of predators and prey do? (FCPPC E Bi)
they fluctuate in cycles. (rise and fall). But this is only in a stable community - if a drought happened or a new predator arrived then the predator-prey cycles would start to change
What is a stable community? (FCPPC E Bi)
when biotic and abiotic factors are in balance.
What is biomass? (PB E Bi)
the mass of all organisms at a certain tophic level.
Biomass is the living tissure of an organism including proteins lipids and carbohydrates.
Why would a scientist dry out all of the organisms that they want to measure the biomass for? (PB E Bi)
because dry biomass is a lot more useful than wet biomass. This is because the moisture content of organisms can vary widely and prodcuce innaccurate results
What percentage of sunlight is absorbed by producers and used for photosynthesis? (PB E Bi)
1%
What does the amount of biomass do as you move up the trophic levels? (PB E Bi)
It decreases
Why does the amount of biomass decrease as you move up the trophic levels? (PB E Bi)
- not all of the material that the bird ingests is absorbed - some is egested as faeces
- some of the biomass that is absorbed is converted into waste products of metabolism and is released - urea in humans
- a large amount of biomass is used by the bird for respiration to release energy (used in movement and some to maintain a constant body temerpature) and create waste compunds (water and carbon dioxide)
What does aerobic respiration release? (PB E Bi)
energy, carbon dioxide and water
Around what percantage of biomass at what tophic level is passes onto the next one? (PB E Bi)
10%
What does the loss of biomass as you move up the tophic levels mean? (PB E Bi)
in most food chains, the number of organisms at each trophic level tends to decrease and there is a very small number of food chains with a large number of trophic levels
How do you calculate the efficiency of biomass transfer? (PB E Bi)
efficiency = gain in biomass / total biomass intake
What does the carbon cycle start with and where? (CC E Bi)
Starts with carbon dioxide in the atmousphere
What is the only way that carbon can enter the carbon cycle? (CC E Bi)
through photosynthesis
How does carbon get back into the atmousphere in the carbon cycle? (CC E Bi)
aerobic respiration
What are the two main processes in the carbon cycle? (CC E Bi)
photosynthesis - brings carbon into the cycle
aerobic respiration - returns carbon to the atmosphere
Describe the carbon cycle: (CC E Bi)
Atmosphere:
carbon dioxide in the atmosphere
plants and algae:
- take the carbon dioxide from the atmosphere by photosynthesis
- the carbon is used for making carbohydrates, fats and proteins which makes up their cells
- they respire so some carbon is released back into the atmosphere as carbon dioxide
animals:
- eat the plants and the algae
- some eat the animals who ate the plants and algae
- the carbon becomes their carbohydrates, fats and proteins for their cells
- they respire so some carbon is released back into the atmosphere as carbon dioxide
- animals produce waste products such as faeces and they all die eventually
decomposing microorganisms:
- bacteria and fungi
- the waste products and dead remains are broken down
- they respire so the carbon from the waste products and the dead remains is returned to the atmosphere as carbon dioxide
- release imernal ions to the soil
fossil fuels:
- under certain conditions, decomposers cannot function effectively so the carbon in the dead remains will slowly be converted to fossil fuels
- a large amount of carbon has been trapped underground as fossil fuels over millions of years
- humans have been buring fossil fuels. this combustion is releaseing a large amount of carbon dioxide back in the atmosphere
Whhy do farmers use compost as a natural fertiliser? (D E Bi)
compost is very rich in the minerals that plants need to grow
What are the names of the optimal conditions for decompositon (conditions that make decomposition take place most rapidly)? (D E Bi)
- temperature
- amount of water
- amount of oxygen
At which temperatures does decomposition take place faster and why? (D E Bi)
warmer because the decomposers use enzymes to break down the plant materials and these enxymes work faster in warm conditions. BUT NOT TOO WARM coz enzymes can denature
Why do compost heaps tend to be quite warm anyway? (D E Bi)
because decomposers release energy when they carry out aerobic respiration
Why is it important that compost does not get too hot? (D E Bi)
the enzymes in the decomposers can denature and the decomposers can die.
What amount of water do microorganisms require to work fastest? (D E Bi)
if the compost is moist it will have the fastest miccroorganisms because many of the chemical reactions in decay require water so it is important that the compost heap does not dry out
Why does compost need to be moist? (D E Bi)
lots of the chemical reactions require water
Why do decomposers need a good amount of oxygen? (D E Bi)
becasue the decomposer microorganisms aerobically respire and it requiers a good amount of oxygen. (compost bin with enough oxgen to enter could have holes in the sides.
What are the ways of allowing oxygen into compost heaps/bins?
- have a compost bin with holes in it so that oxygen can get in
- gardening fork to mix the compost regularly which allows more oxygen to pass into the centre. It also breaks up large clumps and also increases the surface area for decomposers to act on.
What happens if there is no oxygen in the compost? (D E Bi)
the decomposing microorganisms carry out anaerobic decay which produces a mixture of gases including methane <- biogas
What do biogas generatures use?(D E Bi)
plant materials such as food waste or animal manure
When do decomposers produce biogas? (D E Bi)
Under anaerobic conditions
How is methane released? (GW E Bi)
- by bacteria in paddy fields (growing rice)
- cows when they trump
What are both carbon dioxide and methane? (GW E Bi)
greenhouse gases - trap heat in the atmosphere which leads to global warming
What is peer- review and what does it help do?
scientists checking eachothers work and helps to detect false claims and makes sure that research published in scientific journals is valid
What are the consequencses of popular media (newspapers) not being subject to peer review? (GW E Bi)
reporting on global warming can sometimes be oversimplified inaccurate or biased
What is one of the main consequences of global warming? (GW E Bi)
loss of habitats e.g loss of ice levels in the Arctic which will cause the population of arctic organisms such as polar bears to fall as their habitat is reduced
What will happen to aniamls such as birds and insects as temperatures rise? (GW E Bi)
gradually extend their range nothwards towards cooler conditions (malaria can be brought up to the UK)
also migration patterns could change
How will temperatures increasing due to global warming affect plants? (GW E Bi)
spring plants are flowering earlier due to warmer conditions. We may be able to grow grapes in parts of the UK where we cannot today but in other parts of the world it may become too hot to grow the crops that are needed.
