Organisms and their Environment Flashcards
What is a habitat?
The place where an organism lives.
What is distribution?
Where the organisms are found in a particular area.
What are six environmental factors that can affect the distribution of organisms?
- Temperature
- Water availability
- Oxygen availability
- Carbon Dioxide availability
- Nutrient availability
- Amount of light
What are the two ways of studying distribution?
1) Measure how common an organism is in two or more areas
2) compare distribution changes across an area
How does one use a quadrat?
1) Place a quadrat on the ground at a random point within the first sample area.
2) Count and record the number of organisms within the quadrat.
3) Repeat
How do you work out the population size of an area using quadrats?
1) Work out a mean number of organisms per square metre using multiple samples.
2) Multiply this by the area in square metres of the habitat.
What are transects used for?
Looking at the distribution of organisms across an area.
How does one use a transect?
1) Mark out a line in the area you are surveying
2) Collect data using a quadrat at regular intervals along the transect
What is meant by reproducibility?
The aptitude for your results to be reproduced by other companies.
What is a way of increasing the reproducibility of a study?
Using a larger sample size which is more representative of the whole population.
What makes a study valid?
- The study answers the question - this means controlling all other variables apart from the one you are investigating.
- The study is reproducible
What is an advantage of doing a random sample?
It increases the validity of the results.
