Exam term 1 Flashcards
What do the arrows stand for in a food chain/web?
“is eaten by”
What are trophic levels?
The levels of consumers in an ecosystem
What is the difference between an autotroph and heterotroph?
Heterotrophs get energy from other organisms, autotrophs make their own energy
What is productivity?
The amount of energy present at each trophic level
What is the equation for photosynthesis?
6CO2 + 12H2O > C6H12O6 + 6O2 + 6H2O
What is the difference between gross and net primary productivity?
Gross is the total amount, and net is the amount left over after heat loss and waste has occurred. The net amount is then also the amount available to the next trophic level.
What are the three types of ecological pyramids?
Pyramid of numbers, pyramid of biomass, and pyramid of energy
What did the Linnaean system use to classify organisms?
Physical features
What is a clade?
A group of organisms that includes an ancestor species and all of its descendants
What are examples of decomposers?
Bacteria and fungi
What are the four types of bacteria in the Nitrogen cycle?
decomposing, nitrifying, nitrogen-fixing, and denitrifying
What does decomposing bacteria do with nitrogen from wastes and dead bodies?
Turns it into ammonium (NH4+)
What does nitrifying bacteria do?
Turns ammonium into nitrates (this must happen twice in the cycle)
What does nitrogen-fixing bacteria do?
Takes nitrogen from the air and turns it into ammonium
What does denitifying bacteria do?
Turns nitrates into nitrogen gas
Explain the mark recapture formula.
N = (M x n)/m
N = population
M = first sample all tagged
n = second full sample
m = second sample tagged
What are some issues with mark recapture?
Animals can be trap happy or shy, weather can cause animals not to move, tagging can be unreliable, animals can be too rare to catch
What is the SDI formula? Explain it.
SDI = 1 - Sum of n(n-1)/N(N-1)
What is the difference between fundamental and realised niche?
Fundamental = where they can survive, realised = where they have to survive due to being outcompeted for resources
What is a keystone species?
A species with the highest impact on the ecosystem in terms of it population
How can you identify a keystone species?
By looking at who can only be eaten by one organism. The organism who is the only one able to eat that organism is the keystone species
What is carrying capacity?
The maximum amount of a species that an ecosystem can sustain
What is species richness?
A tally of the number of that species in a particular area
What are the two types of factors influencing population size?
Density dependent and independent
What is competitive exclusion?
Two species requiring the same resource cannot exist in the same niche
What is an ecological niche?
A species role and position in its environment
What are the 7 symbiosis?
Mutualism, cooperation, commensalism, amensalism, parasitism, competition, and predation
What are some density dependent factors that influence population size?
competition, birth and death rates, predation, crowding, disease
What are some density independent factors influencing population size?
weather, water availability and quality, salinity and pH, human influence
What does SDI of 0 mean? And an SDI of 1?
0 = monoculture, 1 = infinite variety
Explain SDI
SDI measures species richness and evenness to describe the diversity of an ecosystem
How can organisms lose energy? (Gross - net)
Respiration, heat loss, waste production
What is a limitation of SDI?
It is heavily weighed towards the most abundant species
