Biodiversity Flashcards
Limiting factor
Aspects of the environment which restrict population size
Biotic factors and examples
Living organisms which restrict population growth
Predators, parasitism, competition for food
Abiotic factors and examples
Non living features of the environment that restrict population growth
Sunlight
Temperature
Lag phase
When only a few individuals of a species are present initially, thereby making the rate of growth of the population very slow
Exponential phase
When the population grows rapidly at its maximum rate due to more species being able to give birth
Carrying capacity
Maximum population size that can be sustained over a period of time
What does carrying capacity depend on
The availability of resources
Stationary phase
When there is a slow growth of population. It could be due to competition or the carrying capacity might be reached.
Here the death rate and birth rate are balanced, so they’re at an equilibrium
Environment resistance
Part of the environment that prevents the growth of a population
Five examples of environmental resistance
Predation
Parasitism
Climate
Disease
competition for food
Factors that check population size
Density dependent factors
Density independent factors
Density dependent factors
Density independent factors
Which of these two tend to be either biotic or abiotic
These factors depend on the population size. Tends to be biotic
Factors that do not depend on the population size . Tends to be abiotic
What effect does density dependent and Independent factors have on the population
Density dependent factors slow down the population while density independent factors can lead to a population crash
Decline or death phase
When Death rate is greater than reproduction rate
What do we mean when we say populations and ecosystems are dynamic
That They are constantly changing
What happens when the carrying capacity is exceeded
Density dependent factors increase mortality rate(death rate) , or reduce breeding rate(birth rate) so that the population declines
What happens when the population falls below the set point (carrying capacity)
Environmental resistance is relieved so that the population rises again
Advantage of intraspecific competition
It is important in selective breeding
Niche
Give on example of a niche
The role of an organism within the place where it lives
What an organism eats
GPP
The rate of production of chemical energy in organic molecules by photosynthesis in a given area
Net primary production
The amount of energy left after a substantial amount of GPP has been respired by plants.
NPP represents the potential food available to primary consumers
Net primary productivity
Rate of GPP minus the chemical energy generated in respiration and used up by metabolism of producers (plants )
Species
A group of organisms which share a large number of common characteristics and which can interbreed to produce fertile offspring
Population
A group of organisms of a single species , interbreeding and occupying a particular area
Intraspecific competition
Competition between individuals of the same species
Interspecific competition
Competition between individuals of different species
Can two species occupy the same niche in a specific habitat ?
No, the more the niche overlaps , the more competition there is
Putrefaction
Decomposition by bacteria and fungi breaks down amino acids from dead organisms, faeces and urine back into ammonium ions.
During which process of the nitrogen cycle does putrefaction occur
During amonification
What does rhizobium trade with the root nodules
The bacteria gets food, particularly sucrose , and shelter , while the plant benefits by having amino acids produced by the bacteria
