Topic 5A - Ecosystems and Photosynthesis Flashcards
EQ. Explain the relationship between GPP and NPP. (3 marks)
- NPP=GPP-R
- energy is lost as heat
- to provide energy for active transport
EQ. Suggest why NPP values would be of use to a farmer who wanted to use this land for cattle. (3 marks)
- because cattle are primary consumers
- they gain energy through NPP
- the more energy moving into the cattle, the higher yield they will receive from the cattle
In which part of the chloroplast do the light-independent reactions take place.
stroma
What is the name of the enzyme used by plants to fix carbon dioxide
RUBISCO
What is the immediate product of the light-independent
reactions of photosynthesis
GP
Describe light-dependent photosynthesis.
- occurs in the thylakoid membrane
- light energy excites electrons in the chlorophyll
- electrons travel down the electron transport chain losing energy
- photolysis occurs to break down a water molecule producing oxygen, H+ ions and electrons
- these electrons replace the ones lost in photosystemII
- energy is lost to synthesise ATP in photophosphorylation
- the electrons combine with NADP to form NADPH
EQ. Explain why the value for GPP is lower than the light energy available to the ecosystem (3 marks)
- because not all light falls on the leaf
- some light is reflected
- some light isn’t the right wavelength
Define ecosystem
interactions of biotic and abiotic factors
Define habitat
the place where an organism lives
Define population
all the organisms of one species in a habitat
Define population size/ abundance
the number of individuals of one species in a specific area
What are biotic factors
living factors
What are abiotic factors
non-living factors
Define distribution
where a species is within a particular area
What is interspecific competition
different species compete with each other for the same resources
What is intraspecific competition
organisms from the same species compete with each other for the same resources
How does abudance vary because of abiotic factors
when abiotic factors are ideal for a species, its organism will grow fast and reproduce succesfully and vice versa
How does abundance vary because of biotic factors
cuz of intra and interspecific competition
Give 2 example of how abiotic factors can affect the distribution of organisms
- some plants cannot grow too close to the shoreline because of the high level of salinity
- some plants only grow south facing because of the high solar exposure
Describe a random sampling method to investigate populations in a field
- divide field into a grid
- use random number generator to select coordinates
- to remove bias
EQ. Describe a non-random sampling method to investigate populations in a area where abiotic factors change gradually (4 marks)
- place frame quadrats
- in fixed intervals (every 10m)
- along a transect
- estimate percentage cover by counting occupied squares
Describe how we would measure temperature
thermometer
Describe how we would measure rainfall
rain gauge which is a funnel attched to a measuring cylinder
Describe how we would measure humidity
electronic hygrometer
Describe how we would measure pH
a sample of soil is mixed with water and an indicator liquid (litmus). it is matched against a chart to determine the pH of the soil.
Describe how we would measure water content
the mass of a sample of soil is measured before and after being dried until it reaches a constant mass. find the difference in mass as a percentage.
EQ. Explain how ecosystems have developed on Surtsey since 1965 (6 marks)
- primary succession took place
- pioneer species took place
- these produced soil called humus
- and provided minerals and nutrients for plants to grow
- habitats and niches are provided for animals
- herbaceous shrubs and trees become established and climax community is established
