bio Flashcards
(4.1) define “population”
a population is the total number of individuals of one species in a particular habitat at a particular time
(4.1) define “community”
a community is formed of the populations of all the species present in an ecosystem at a particular time
(4.1) define “habitat”
a habitat is where specific organisms live
(4.1) define “ecosystem”
a group of living organisms and their environment
(4.2) practical: investigate the population size of an organism in two different areas using quadrats
how to use a quadrat (commonly sized 50cm*50cm or 0.25m^2)
- place it on the ground
- count the number of individuals of our chosen species inside the quadrat
- some individuals might be half in/out, count the ones at the top and left edge for consistent data
- estimate a percentage for difficult to count species (e,g, grass)
to find the population in a habitat
- calculate the area of the habitat
- measure number of individuals, repeat many times for a reliable result (at least 10)
- calculate the average of individuals in a quadrat
- calculate how many quadrats fit into the area of the habitat
- multiply the average individuals by the number of quadrats
Use random sampling (valid data)
- layout two tape measures at right angles to create a 10m by 10m set of axes
- generate 10 pairs of numbers between 0 and 10 to create coordinates
- place the quadrat at the coordinates (place the bottom left of the quadrat exactly at the point)
when habitats are not uniform, changes in abiotic factors
- pick two contrasting areas of the habitat and set up a 10m*10m grid
-use random sampling
- compare average results
OR
- use a transect, a line across a habitat over a range of abiotic factors
- place quadrat at regular intervals along the transect to measure the number or % cover of the species
(4.5) how abiotic factors affect the population size and distribution of organisms
- abiotic means non-living
such factors include - light intensity, for photosynthesis, affects growth, limiting factor
- temperature, affects rate of photosynthesis, enzymes, metabolism, cold-blooded creatures, limiting factor
- water/moisture level, require for survival, photosynthesis
- soil pH/nutrients/minerals, different species require/adapted to different conditions
- wind intensity/direction, affects transpiration rate and photosynthesis
- CO2 level, required for photosynthesis, limiting factor
- O2 level, affects aquatic animals
(4.5) how biotic factors affect the population size and distribution of organisms
- biotic means living
such factors include - food, affects survival rate
- new predators, affects the population of what it consumes
- new pathogens/diseases, affect the population for species that have zero immunity/resistance to it
- competition, survival of the fittest and best adapted, can lead to the extinction of one species
(4.6) list the names of each trophic level
- decomposers
- producers
- primary consumer
- secondary consumer
- tertiary consumer
(4.7) what is the pyramid of number
- a pyramid of numbers shows the total number of individual organisms at each level in the food chain of an ecosystem.
- does not always have a regular pyramid shape
(4.7) what is the pyramid of biomass
- represents the biomass present at each trophic level
(4.7) what is the pyramid of energy transfer
- a model that shows the flow of energy from one trophic level to the next along a food chain
and the energy per square metre found at each level
(4.8) how are substances or energy transferred along a food chain/web
- energy is transferred along food chains by being consumed.
- the amount of available energy decreases from one trophic level to the next.
(4.9) why only 10% of the energy is transferred from each trophic level to the next
- 90% of the starting energy is unavailable to the next trophic level because that energy is used for processes such as movement, growth, respiration (ATP), and reproduction.
- energy is also lost by metabolic heat and waste (e.g.faeces)
- some parts are not eaten such as bones and hair
(4.10) describe the stages in the carbon cycle
- carbon atoms from CO2 in the air is formed into glucose via “photosynthesis”
- glucose is broken down in the plant via “respiration”, the carbon forms into CO2 and is released into the air
- carbon compounds in the plant will be “eaten” by animals. via respiration, carbon is released into air as CO2
- when animals and plants die, decomposers (bacteria and fungi) will feed on them. by respiring, the carbon is released into the air as CO2
- when things are not fully decayed, they are “fossilised” due to conditions in the soil. fossil fuels are formed over millions of years by “locking in”
- fossil fuels are burned (“combustion”) and CO2 is released back into the air
(4.13) what are the greenhouse gases
- water vapour
- carbon dioxide
- nitrous oxide
- methane
- CFCs, chlorofluorocarbons
(4.14) how human activities contribute to greenhouse gases
- CO2 emitted via car exhaust, industrial processes, burning of fossil fuels
- deforestation
- methane from rice and cattle ranching
- nitrogen oxide from fertilisers, vehicles engines and industry
- CFCs from aerosols
(4.15) how an increase in greenhouse gases results in an enhanced greenhouse effect and
that this may lead to global warming and its consequences
- melting polar ice caps, increase in sea levels, flooding
- habitat destruction, grasslands turn into deserts, loss of habitat for resident species, lead to extinction
- drought and desertification, crop failures, food shortage, famine
- increased extreme weather events, e.g. hurricanes
- new diseases, warmer temperature in more countries means disease-carrying organisms to survive in a larger area. permafrost/ice melt to expose the world to prehistoric pathogens.
- increase in heat-related illnesses and deaths
- change in crops, e.g. growing olives and grapes in England as temperature rise. beneficial to some.
(2.65) describe the structure of the heart and how it functions
- blood flows from the vena cava to the right atrium
- right atrium through the tricuspid valve to the right ventricle
- right ventricle through semi-lunar valve to pulmonary artery
- pulmonary artery through the lungs to the pulmonary vein
- pulmonary vein to left atrium
- left atrium through bicuspid valve to left ventricle
- left ventricle through semi-lunar valve to aorta
- wall of the left ventricle is thicker than the right to pump blood at a higher pressure so the blood can reach the whole body
- right and left separated by the septum
- atria contract, blood emptied to the ventricle
- ventricle contract, pushes blood into arteries
- valves prevent blood flowing backwards
- diastole, relaxed, blood flows in
- ## systole, contract, blood flows out
(2.49) how the biological consequences of smoking in relation to the lungs and the circulatory system
- carbon monoxide irreversibly binds into haemoglobin, reduces oxygen transported
- chemicals kill cilia cells, increase in mucus production, mucus build up as less cilia move it, “smoker’s cough”, increased risk of infection,
- bronchitis, from built up infected mucus
- emphysema, break down of alveoli wall/fusing, less surface area for diffusion, kill around 20k people in UK per year
- CHD, increase the formation of plaque, high blood pressure
(2.67) what factors and how they may increase the risk of developing coronary heart disease
- DIET, lots of saturated fats increases cholesterol, increase risk of fatty deposits
- SMOKING, increase of blood pressure, risk of fatty deposits
- HIGH BLOOD PRESSURE, damage artery lining, risk of fatty deposits
- HIGH SALT LEVELS, leads to high blood pressure
- OBESITY, increase blood pressure
- LACK OF EXERCISE, high blood pressure
(2.10) what are the roles of an enzyme in a reaction
a catalyst that increases the rate of reaction without being used up itself in the reaction
(2.11) how temperature can affect the functions of an enzyme
- increase in kinetic energy
- enzyme and substrate move faster
- faster movement
- more successful collisions
(2.36) describe the differences between aerobic and anaerobic respiration
- Aerobic respiration takes place in PRESENCE of oxygen; whereas anaerobic respiration takes place in ABSENCE of oxygen.
- CO2 and WATER are the end products of aerobic respiration, while LACTIC ACID is the end product of anaerobic respiration.
- Aerobic respiration releases MORE ENERGY than anaerobic respiration.
(2.37) the word equation for aerobic respiration
glucose + oxygen ==> carbon dioxide + water
(2.37) the balanced chemical equation for aerobic respiration
C6H12O6 + 6 O2 ==> 6 CO2 + 6 H2O
(2.38) the word equation for anaerobic respiration for animals and plants
glucose ==> lactic acid
glucose ==> ethanol + carbon dioxide
(5.6) practical: investigate the role of anaerobic respiration by yeast in different conditions
Change - temperature (10,20,30,40)
Organism - yeast
Repeat - 3 times per temperature and mean
Measure - number of bubbles or volume of CO2 produced over a set time
Same - time taken (in water bath and taking the result), mass of yeast, mass of glucose
