B7- Using Quadrats Flashcards
What is a habitat?
The place where an organism lives
What is the distribution of an organism?
Where an organism is found
What factors affect the distribution of an organism?
Environmental factors
What are two methods to study the distribution of an organism?
- Measure how common an organism is in two sample areas
- Study how the distribution changes across an area
What is a quadrat?
A square frame enclosing a known area, e.g. 1 m²
What are the steps to compare how common an organism is in two sample areas using quadrats?
- Place a quadrat on the ground at a random point
- Count all the organisms within the quadrat
- Repeat steps as many times as possible
- Work out the mean number of organisms per quadrat in the first sample area
- Repeat in the second sample area
- Compare the two means
How do you calculate the mean number of organisms per quadrat?
Total number of organisms divided by the number of quadrats
If Anna counted daisies in 7 quadrats with results: 18, 20, 22, 23, 23, 23, 25, what is the mean?
22 daisies per quadrat
What is the population size of an organism also known as?
Its abundance
In the example provided, how did students estimate the population of daisies on a field?
- Found a mean of 10.5 daisies per quadrat
- The field area was 800 m²
- Mean number of organisms per m² was calculated
- Multiplied the mean by the total area of the habitat
What was the mean number of daisies per m² in the example given?
21 daisies per m²
How is the total population of daisies on the field estimated?
Multiply the mean by the total area of the habitat
Fill in the blank: A quadrat is used to study the _______ of small organisms.
Distribution
True or False: The area of the quadrat affects the mean number of organisms calculated.
True
