LS7B FINAL!!! EXAM BEST ANSWERS 2024-
2025 WITH 100% GUARANTEED SOLUTIONS
Ecology
the study of how organisms interact with other organisms and their physical environment.
Two Types of factors from an environment
Abiotic factors:
- non-living parts of an environment
Biotic factors
-living parts of an environment
Biosphere
al organism and environment of the planet
Population Ecology
a subfield of ecology that studies how the range, size, and density of population change over
time.
Density
number of organisms in a unit of area
Biomass
amount of living material (the greater the organisms, the greater the biomass)
The Spatial Distribution of Organisms: Uniform
equally spaced. caused often by the result of negative interactions among individuals such as
competition, however pretty rare
The Spatial Distribution of Organisms: Clumped
clustered in groups. suitable habitat or resources are found in patches, also herds.
The Spatial Distribution of Organisms: Random
,the position of one individual is independent of another. the scattering of plants seeds by the
wind can lead to a random distribution of plants after the seeds (something)
Population Growth Rate
the rate at which a population increases
Per capital growth rate(r) :
average individuals contribution to total population's growth rate (equation, deltaN / delta T =
rN)
Population Growth
if on average individuals are having more than one offspring, then we would expect the
population to grow exponentially. However, this is not possible due to the carrying capacity and
instead we see that population grows logistically
Density Dependent Factors
Factors that affect population size proportionally to the density of population
ex: competition, predation, and disease
Density Independent Factors
factors that influence population size regardless of population density
ex: drought, temperature (often abiotic)
Carbon Cycle
the series of processes by which carbon is moved in the environment
Source
places to get carbon, back into the atmosphere
Sink
places that carbon is taken in or removed from the environment
Scales of Time: Long-Term
thousands of years
Scales of Time: Short-Term
happens quickly (couples of years or organisms life time)
R-Strategist
, organisms with high fecundity (a lot of offspring), but have a low chance of survival.
-small
-low energy required to reproduce
- have a lot of offspring
- short life expectancy
- type 3 of survivorship graph
-unstable environment
K-Strategist
organisms with low fecundity (fewer number of offspring) and put a lot of energy to ensure they
survival.
ex: mammals, humans
-large size
- lot of energy required to reproduce
-few amount of energy
-type 1 or 2 survivorship graph
- stable environment
Survivorship Curves: Type 1
A high percentage of offspring survival at young and middle years but survival decreases at
older ages (k)
Survivorship Curves: Type 2
equal chance of survival at all ages
Survivorship Curves: Type 3
very few organisms survive younger years however those who survive to old ages live for a long
time
How to Study a Population
Scientist usually study populations by sampling, which involves counting individuals within a
certain area or volume that is part of the population's habitat
Quadrant (Form of studying a population)
using a square within all individuals are counted, used for immobile/sessile organisms
Mark and Capture (Form of studying a population)
2025 WITH 100% GUARANTEED SOLUTIONS
Ecology
the study of how organisms interact with other organisms and their physical environment.
Two Types of factors from an environment
Abiotic factors:
- non-living parts of an environment
Biotic factors
-living parts of an environment
Biosphere
al organism and environment of the planet
Population Ecology
a subfield of ecology that studies how the range, size, and density of population change over
time.
Density
number of organisms in a unit of area
Biomass
amount of living material (the greater the organisms, the greater the biomass)
The Spatial Distribution of Organisms: Uniform
equally spaced. caused often by the result of negative interactions among individuals such as
competition, however pretty rare
The Spatial Distribution of Organisms: Clumped
clustered in groups. suitable habitat or resources are found in patches, also herds.
The Spatial Distribution of Organisms: Random
,the position of one individual is independent of another. the scattering of plants seeds by the
wind can lead to a random distribution of plants after the seeds (something)
Population Growth Rate
the rate at which a population increases
Per capital growth rate(r) :
average individuals contribution to total population's growth rate (equation, deltaN / delta T =
rN)
Population Growth
if on average individuals are having more than one offspring, then we would expect the
population to grow exponentially. However, this is not possible due to the carrying capacity and
instead we see that population grows logistically
Density Dependent Factors
Factors that affect population size proportionally to the density of population
ex: competition, predation, and disease
Density Independent Factors
factors that influence population size regardless of population density
ex: drought, temperature (often abiotic)
Carbon Cycle
the series of processes by which carbon is moved in the environment
Source
places to get carbon, back into the atmosphere
Sink
places that carbon is taken in or removed from the environment
Scales of Time: Long-Term
thousands of years
Scales of Time: Short-Term
happens quickly (couples of years or organisms life time)
R-Strategist
, organisms with high fecundity (a lot of offspring), but have a low chance of survival.
-small
-low energy required to reproduce
- have a lot of offspring
- short life expectancy
- type 3 of survivorship graph
-unstable environment
K-Strategist
organisms with low fecundity (fewer number of offspring) and put a lot of energy to ensure they
survival.
ex: mammals, humans
-large size
- lot of energy required to reproduce
-few amount of energy
-type 1 or 2 survivorship graph
- stable environment
Survivorship Curves: Type 1
A high percentage of offspring survival at young and middle years but survival decreases at
older ages (k)
Survivorship Curves: Type 2
equal chance of survival at all ages
Survivorship Curves: Type 3
very few organisms survive younger years however those who survive to old ages live for a long
time
How to Study a Population
Scientist usually study populations by sampling, which involves counting individuals within a
certain area or volume that is part of the population's habitat
Quadrant (Form of studying a population)
using a square within all individuals are counted, used for immobile/sessile organisms
Mark and Capture (Form of studying a population)
