The organism in the enviornment Flashcards
How can you define a population?
A group of organisms of the same species living in the same place at the same time
How can you define a community?
Includes all of the population living in the same area at the same time
How can you define a habitat?
It is a place where an organism lives
How can you define an ecosystem?
All the biotic factors and all the abiotic factors that interact within an area at one time
What can you use quadrant for?
To measure the abundance of:
- The number of individual species
- Species richness (The total number of individual species)
- Percentage cover
How do you calculate percentage cover?
Divide the number of squares covered by e.g grass by the total number of squares in the quadrant, then multiply this by 100
What apparatus would you need to investigate the population size in 2 areas using quadrants
- 2 Tape measures
- A quadrant
- A Random Number generator
- A Species key
What is the method to investigate this?
- Use the two tape measures to lay out a survey area (e.g. 10cmx10cm) in your chosen area.
- Use a random number generator to create a set of coordinates to place your first quadrant (e.g. if you get a 4 and then a 5, then place your quadrant on X-axis 4 and Y-axis 5.)
- Count the number of your chosen species inside your quadrant.
- Estimate the population of your chosen species using this equation: Total Area/ Area sampled x total number of your chosen species counted.
What are the limitations to the Investigating population size in 2 different areas using quadrats meothod?
- It can be easy to miss individual organisms
-It may be hard to identify different species
Solutions - Use a pencil or stick to move useless objects like leaves or rocks out of the way which could be potentially hiding organisms
- Use a species key to identify the different species
For the Investigating population size in 2 different areas using quadrats method how should your evaluation look like?
C: We are changing the study area where we are collecting the data (This is the change)
O: We will count the same species of organism on the quadrant
R: We will repeat this investigation multiple times to ensure reliable results ( This is the repeat)
M1: We will count the number of designated study species found across all the quadrants
M2: Not relevant in this scenario but (What time scale will you use)
S: We will control the size of the quadrant, the way the quadrant is placed, the day the results were collected, the weather etc.
What is an abiotic factor?
A non-living factor that is in the environment eg Light intensity, temperature and wind speed
What are some of the main abiotic factors? And how do they affect a community?
-Light intensity (Needed by plants for photosynthesis. If light intensity increases then plant growth rate will follow)
- Temperature (Affects the rate of photosynthesis in plants)
- Moisture levels (Plants and Animals require water to survive)
- Soil Ph levels and material content (Different species of plants require different soil Ph levels and soil mineral content)
- Wind intensity and direction (Affects transpiration rates in plants, this affects the rate of photosynthesis as it ensures water and mineral ions are transported to the leaves)
- CO2 levels for plants (CO2 is required for photosynthesis, CO2 concentration will affect the rate of photosynthesis
- Oxygen levels for aquatic animals (Some aquatic animals like fish can only survive if the water has a high oxygen concentration.)
What are some of the main Biotic factors?
- Availibiilty of food
- New predators
- New pathogens
- Competition
How does Availability of food affect a community?
More food means organisms have a higher chance of surviving and, therefore a higher chance of reproduction and survival. (e.g. Rainforests have a rich food supply, which allows many species to live in it, compared to a desert, which has a low food supply and, therefore relatively few species live in it.)
How does New predators affect a community?
In a balanced ecosystem, predators can eat to survive but not too many that they wipe out a population. But if a new predator appears then it can break the delicate balance of the ecosystem.
