Populations Flashcards
Define Habitat
The place where an organism lives
Define Population
All the organisms of one species in one place at one time
Define Community
Populations of different species in a habitat at one time
Define Ecosystem
All the organisms and abiotic conditions in a particular area
Define Abiotic conditions
Non-living features of an ecosystem eg/ temperature, light
Define Biotic Conditions
Living features of an ecosystem eg/ predators, food
Define Niche
The unique role of a species within a habitat eg/ what it eats, when and where it eats
Define Adaptation
A feature that members of a species have that increases their chance of survival to reproduce and pass on their genes eg/ being camouflage
What happens to two species trying to occupy the same niche?
-Compete with each other -One will have an advantage over the other -The weaker species will die out until only the successful remains
What if two species appear to occupy the same niche?
There will be slight differences eg/ different food sources
What are the two types of adaptation?
-Physiological (processes inside the body) -Anatomical (structural features of their body)
Define Abundance
The number of individuals of one species in a particular area
Define Frequency
The number of samples a species is recorded in
Define Percentage Cover
How much of the area investigated is covered by the species (plants only)
Define distribution
Where a species is within the area investigated
Name the five steps in taking a general sample
-Choose an appropriate area within the the total are being investigated -Sample randomly to avoid bias eg/ grid and coordinates from a random number generator -Appropriate sampling technique -Repeat to make more reliable -Estimate for the whole area by averaging the data collected and multiplying by the size of the whole area
Name two methods used to investigate ground insects
-Pitfall traps -Pooters
Name the three types of transects
-Line transect (record species touching the transect) -Belt transect (work out species frequency and percentage cover between to lines) -Interrupted transect (take measurements at intervals)
Name the five steps in mark-release-recapture
-Capture and count a sample of a species -Mark them in a harmless way (give example) -Release them back into their habitat -Wait a week then take a second sample -Count how many of the second sample are marked
What is the mark-release-recapture equation
total population size = (sample 1 x sample 2)/marked in sample 2
Name two things you must consider before doing fieldwork
-Risk assessment -Ethical Issues (affect on environment and organisms)
What should you include when describing data?
- General trends
- Example of each place it changes
What should you include when interpreting data?
- Describe correlation between factors
- Suggest a conclusion
- Allow for other actors
- Suggest a reason for the conclusion
Describe how abiotic factors affect population size
-With ideal abiotic factors organism can grow fast and reproduce successfully -With non ideal abiotic factors population size will decrease as more energy is used in other ways
