Yr 13 - Chapter 23 - Ecosystems Flashcards
What is a climax community
When the community is not subject to future succession; it is stable
What laboratory equipment would you select to make an accurate measurement of the length of a protoctist
Light Microscope
Graticule
What nitrogenous excretory molecule from the decomposers would pass to the next stage of the nitrogen cycle?
Urea
What steps are undergone for nitrogenous compounds to be uptaken by plants
Nitrosomonas bacteria help convert nitrogenous compounds to nitrites
Nitrobacter help convert convert nitrites to nitrates
Nitrates are highly soluble so enters the plant
What is nitrogen fixing bacteria?
Azobacteria and Rhizobium contain the enzyme nitrogenase which combines N2 with H2 to produce NH3
Describe the similarities between the nitrogen cycle and the carbon cycle?
Nitrogen and carbon are both inorganic gases and found in the atmosphere.
Nitrogen and carbon are both first primarily found in plants. The transfer of these elements is when animals feed on the plant.
Both carbon and nitrogen have decomposers. Microorganisms return the element to atmosphere. CO2 during decomposition and N2 by denitrifying bacteria.
What is the process called for:
I) producers to CO2 in the atmosphere
ii) CO2 in the atmosphere to producers
I) Respiration
ii) Photosynthesis
What abiotic factor is likely to affect the growth of young ash tree?
The availability of light underneath larger trees in the wood
Which bacteria converts ammonium compounds to nitrites
Nitrosomonas
What process in the nitrogen cycle occurs under anaerobic conditions?
Nitrogen Fixation
Outline how the percentage efficiency of energy transfer between producers and herbivores can be estimated.
To obtain the calculation you would sample producers and sample primary consumers under the same area.
Measure the dry mass and measure the energy content
Then use the formula:
primary consumer energy / producer energy * 100
Describe the difference between a pioneer community and climax community
Pioneer community is before climax community.
Pioneer community has lower biodiversity
Describe the differences between decomposition and denitrification
Decomposition is the break down of dead material
Decomposition is conversion of organic matter to inorganic
Denitrification conversion of nitrates to nitrogen gas
Describe the differences between nitrogen fixation and nitrification
Nitrogen fixation is the conversion of nitrogen into ammonia
Nitrification is the conversion of ammonia into nitrite
Suggest a biotic factor that affects the distribution of buttercups
Predation / Competition
What is the significance of a keystone species
It has a significant effect on the ecosystem as many other species rely on it
Where are the location of the bacteria :
Rhizobacterium
Nitrosomonas
Nitrobacter
Denitrifying bacteria
Root nodules
Soil
Soil
Soil
Suggest why the concentrations of CO2 in the atmosphere increases during the winter months and decreases during the summer months
Less photosynthesis
What are the properties of pioneer community?
species produce large numbers of wind-carried seeds or spores
biomass is low
many species are lichens and mosses
State the collective name of the animal and plant populations that are present at the end of primary succession.
Climax community
Describe how the student would use a belt transect to investigate the distribution of the two buttercup species.
lay tape measure out from edge of pond
place quadrat beside tape measure
identify species of buttercup in quadrat
count number of plants of each species (in quadrat)
repeat for positions of quadrat along tap
State two developments, other than selective breeding, that could account for the total increase in wheat yield
Use of fertilisers
Use of pesticide
Explain how the follow activities could have contributed to increase habitat diversity
- Constructed dams
- Felled trees
- Built lodges
- Water for aquatic species
- Opened up tree canopy allowing light to enter ground level
- Creates sheltered habitats
Increasing habitat diversity may lead to an increase in species diversity and genetic diversity
Explain why
Species diversity will rise as more species life in new habitats
Genetic diversity will increase as species have a wider range of conditions to live in
