Bio 20, Unit 2, Part 1 & 2 *FINAL* Flashcards
Define biotic
Living parts of the biosphere (organisms)
Define ecology
The relationships among organisms (biotic), and between organisms and their environment (abiotic).
Define abiotic
Non-living parts of the environment (light, soil, water, air, rock)
What is a trophic level?
Each step in the transfer of energy and matter in a community
Define scavenger
Consumers that feed on the tissues of dead organisms
Define decomposers
Organisms that feed on and break down organic matter (bacteria and fungi)
Define biomass
The total mass of a population of an organism in an area
What are the three main biochemical cycles?
1) water cycle
2) carbon and oxygen cycle
3) nitrogen cycle
Define bio magnification
The increase in the concentration (amount) of a substance as it moves up through the trophic levels in the food chain.
What percentage of energy is lost to daily activities?
90%
Define steady state/ homeostasis
A state of balance
Energy is continually supplied and matter gets recycled
Define population
A group of individuals of the same species, in a specific area, at a specific time.
Equations for density
N
D S
Define density
The number of individuals per unit of space that they occupy
Define Rate of Population Change
How fast the population id changing with respect to time.
Rate of Population Change equation
Rate of
What are the 4 determiners of population size?
Natality
Mortality
Immigration
Emmigration
Define limiting factors
Any condition of the environment (living or non living) that limits the size or a population.
Formula for population size using the 4 determiners.
(pop2-pop1) divided by (time2-time1)
What are the 3 main mortality patterns?
Late Death
Early Death
Moderate Death
What are the 7 main limiting factors?
Predators(b) Climate(a) Disease (bacteria/viruses) (b) Water (a) Pollution (a) Competition for food (b) Parasites (b)
What is the reproductive strategy for late death?
Have few offsprings at a time and care for them until maturity.
What is the reproductive strategy for early death?
Have many offsprings (100s) at a time and provide no care.
What is the reproductive strategy for moderate death?
Have a medium number of offspring (10s) and may provide little or no care.
What is exponentially/j-shape?
Population growth at an increasing rate
Define carrying capacity
The maximum number of individuals an area can support.
What growth pattern is a natural population that reaches a carrying capacity?
S-shaped
Define population cycle
When fluctuation occurs regularly in a pattern (predictable)
Describe a a population in a closed environment.
1) j-shaped: lots of food and space
2) s-shape: reached carrying capacity limited food and space
3) fluctuates to extinction
