topic four Flashcards
what is a species
a group of genetically similar living organisms that are able to interbreed and produce fertile offspring. Fertile offspring are those which can in turn interbreed and pass on their genes to another generation.
population
A group of organisms of the same species that live in a particular area at the same time.
community
A group of populations living and interacting in a particular area.
ecosystem
A community and its abiotic environment.
abiotic factors
Non-living factors, such as pH, salinity, wind speed, type of soil, etc.
biotic factors
Living factors in an ecosystem, such as the plants and animals.
autotroph
Organisms that are capable of making their own complex organic molecules from carbon dioxide and other simple compounds are called autotrophs
heterotroph
Organisms that obtain their organic compounds through feeding on other organisms are called heterotrophs.
consumers
organisms that gain nutrients by feeding on other organisms using ingestion or absorption.
primary consumers feed only on
autotrophs
secondary consumers feed on
primary consumers
teritary consumers feed on
secondary consumers
omnivores
consumers who feed on both producers and consumers.
detritivores
heterotrophs that obtain their organic nutrients from detritus, which is waste or other organic debris, by internal digestion.
internal digestion
the process by which an organism digests its food inside of its body, usually with the aid of a digestive tract.
saprotrophs
organisms that get their nutrients by secreting digestive enzymes into their environment to break down organic debris around them.
extracellular digestion
the process by which organisms secrete enzymes into their environment to break down organic debris around them.
ecology
the study of relationships between living organisms and their interactions with their environment
mutualism
symbiotic rel where both parties benefit
commensalism
where one organism benefits and the other is unaffected
parasitism
when one organism benefits and the other is harmed
A predator-prey relationship is one in which
one organism hunts and feeds on another.
community
a group of populations of different species living in the same area and interacting with each other.
nutrient cycle
advantages of mesocosms
Treatments are easily replicated.
The effect of several environmental factors can be tested.
Food webs can be established.
Direct and indirect effects can be studied.
Contamination influence can be evaluated.
Constants can be controlled to see the effect of one environmental factor at a time.
The sustainability of an ecosystem can be tested
what does chi quared test
how likely it is that an observed distribution is due to chance. categorical data only
what is the null hypothesis
the hypothesis that states that there is no association between the two populations being tested in the chi-squared test.
The ecological frequency is
the number of times a plant species occurs in a given number of quadrats. Frequency is usually expressed as a percentage and is sometimes called a Frequency Index.
expected frequency is calculated y
multiplying the row total by column total and dividing by the grand total
Row total×Column total/Grand total=Expected frequency
expected frequency
the number of quadrats a population is expected to occupy in an area.
chi squared formula
x2=Σ(O−E)^2/E
Χ 2 = the test statistic
∑ = the sum of
O = Observed frequencies
E = Expected frequencies
X 2 calculated >X 2 critical:
H 0 is rejected and the variables are associated
X 2 calculated ≤ X 2 critical:
H 0 is accepted and the variables are not associated
quadrat
a tool used to measure population distribution in a given area. It is often made in a square shape.
random sampling
necessary in order to obtain data that is random and unbiased.
The energy that is contained in the carbon compounds consumers ingest is used for the following cellular activities (this is not a complete list):
Nucleic acid and protein synthesis
Ion exchange across membranes
Cell division for reproduction, growth and repair
Movement of components within cells.
how is atp generally produced
by oxidising, or breaking down, glucose and other carbon compounds through the process of respiration
food chain
a model that shows how nutrients and energy are passed from producer to primary consumer, then secondary consumer, and so on. It clearly shows how each organism in the chain gets its food as well as the direction the energy flows through the chain. Food chains generally begin with plants and end with animals.
which way do the arrows point in food chains
direction of nutrient and energy flow
food web
shows the interconnections that exist among food chains. In a food web, each organism may have several sources of nutrition, or may be a source of nutrition for several other organisms.
how is energy lost in food chains
bones not eaten
fur not eaten
faeces
heat