Biodiversity and the environment Flashcards
What is an advantage of using biological control?
There is no need to use harmful chemicals such as weed killers.
What problems can arise from biological control?
- The organism that aims to control the crop become a pest itself.
- The organism used to control could also eat other plants/animals as well as the pest species.
- This method does not remove the pest entirely.
What is biological control?
Biological control uses the natural predator or parasite of a pest to control its numbers.
What problem can alien/invasive species cause?
It can become dominant and spread, which means it grows quickly and outcompetes the native species.
What could the result be of an alien or invasive species becoming dominant?
The native species cannot compete for resources, and as a result, these native species can die out with the alien species becoming a pest.
What is the definition of an invasive species?
A species whose numbers grow faster that native species and upset the ecological balance.
What is the definition of an alien species?
A species which is not native to a particular region or country. Sometimes an alien species can become invasive
What is the ‘Total in population’ formula for the mark and capture technique.
(number of animals marked) x (number caught the second time) divided by the number of animals marked that were caught the second time.
What is the mark and recapture technique?
- Used for animals that move about.
- Catch approximately 30 animals and mark them safely.
- Leave the marked animals to return to his population and mix with the rest of the population that have not been marked.
- A day later catch as many animals as is possible e.g. 100 and count the number that are marked.
What is Transect?
A tape that measures distance.
Define Transect?
To discover distribution - the way in which living organisms are spread over an area.
Transect is used to?
Looks at the types of living things and how they change from place to place. For example low tidal area to shore area of a beach.
How is Transect used?
Note the types of plants/animals that touch the line at different distances.
How do you ensure the reliability of the data whilst using Transect?
Use transect a number of times in the same area.
How do you ensure the reliability of the data whilst using Quadrat?
Use the quadrat a number of times and calculate an average value.
Define Quadrat?
To discover abundance - the quantity or amount of living organism present in a particular area.
How is Quadrat used?
Estimates the number of living things in a large area. For example number of dandelions in a field.
What is Quadrat?
A metal or wooden frame with a side measuring 0.5m or 1m.
How is a Quadrat used?
It is randomly thrown and then the number of plants/animals within the square are counted.
What is biodiversity?
Biodiversity is the number of different species of plants and animals in a particular habitat.
Name five reasons biodiversity is important to living things?
- Provide food.
- Have the potential to become food.
- Used as raw materials for industry.
- Are important for human welfare.
- Have the potential to be used in new medicines.
Name three reasons biodiversity is important to the ecosystems?
- Manage the atmosphere (e.g. green plants absorb carbon dioxide)
- Ensure water supplies.
- Ensure fertile soils.
Name four ways habitats are destroyed?
- Quarrying.
- Landfill.
- Building.
- Agriculture.
What are the repercussions of habitat destruction?
The species will disappear and there will be a decrease in biodiversity.
