T1 - Organisms in the environment Flashcards
Examples of abiotic factors
water availability, light intensity and mineral ions
What is a transect?
lines used to help find out how organisms (like plants) are distributed across an area, e.g. if an organisms becomes more or less common as you move from a hedge towards the middle of a field
Transect sampling method
- stretch a tape measure through the area you wish to sample
- place a quadrat along the transect at the beginning and record the number of individuals in the transect
- repeat by moving your quadrat along the transect at regular intervals and recording the number of individuals in each quadrat
- repeat the transect at different places in the sample area
Measuring biodiversity
Use 2 tape measures to lay out your first survey area (e.g. 10m X 10m)
Use a random number generator to create a set of coordinates to place your first quadratE.g. for coordinates 4,5, you would place your quadrat 4m along on the x-axis and 5m along on the y-axis
Count the number of different species found within that quadrat
Repeat this process until you have collected the data for 10 quadrats
Repeat these steps for the second survey area
population
a group of organisms of the same species living in the same place at the same time
community
all of the populations living in the same area at the same time
what is it called if one species is removed from within a community that causes an effect on the rest of the community?
interdependence
habitat
Place where an organism lives
ecosystem
all the biotic factors and all the abiotic factors that interact within an area at one time
biotic factors
All of the living components of an ecosystem
abiotic factors
Nonliving components of environment.
examples of biotic factors
plants, animals, fungi
Ecosystems (size)
Ecosystems can vary greatly in size and scale A small ecosystem might be a garden pond A large ecosystem might be the whole of Antarctica
individual
single member of a species
What does ecology study?
The distribution of species
The abundance of species
Interactions between species
Interactions between a species and its abiotic environment
what piece of equipment is used to investigate population size
quadrat
what is a quadrat?
a quadrat is a square frame used to measure abundance, they are placed on the ground and the organisms within them are recorded
Quadrats used in an investigation
- lay a quadrat randomly (using a grid and random number generator)
- count the number of individuals in each quadrat
- repeat with several quadrats and find the mean per quadrat
- calculate the ratio of quadrat area to study size area
- multiply your mean number of plants by this ratio to calculate how many in the study area
using CORMS when explaining practical work
C - change. What is being changed?
O - organism - control related to the organism
R - repeat - repeats must be carried out for reliable results
M - measurement 1 - how will you measure your dependent variable
- measurement 2 - what time scale will you use to measure your dependent variable?
S - same - what will you control in the experiment?
Biodiversity
the range and variety of different species of organisms on Earth, or within an ecosystem
species richness
the number of different species in a community
Example of high biodiversity
an environment with lots of different species which show a lot of variation and are living in, all evenly distributed across the study area
human activities which are reducing biodiversity
waste production, deforestation, global warming
Why is biodiversity important?
- stable food chain/ecosystem
- nutrient cycle/soil structure
- new medicine/food/resources
- tourism
what example demonstrates the importance of biodiversity in an ecosystem?
a food chain
how do abiotic factors influence organisms
more access to light intensity - plant growth increases
temperature - temperate weather/conditions are best as too hot or too cold conditions could kill off organisms
availability of water - keeps organisms healthy and alive
availability of oxygen and carbon dioxide - increases plant growth
how do biotic factors influence organisms
food availability - increases plant growth
new pathogens - decreases plant growth/organism growth
new predators - decreases plant/organism growth
competition with other organisms - decreases plant/organism growth
