BIO 1500 chapter 3
1. Populations are stable (TRUE OR FALSE): FALSE
2. study of the vital statistics of populations and how they change over time: de-
mography
3. Populations are a ....: dynamic entity (contains fluctuations, it changes)
4. What is DENSITY?: number of individuals per unit area or volume.
5. What is DISPERSION?: pattern of spacing among individuals within the population's boundaries
- how much they are spaced out
6. What are the 2 main things that is used to describe the population?: - Size (N):
total number of individuals
- Density: number of individuals within a specific area
7. How do population ecologists determine the size of immobile organisms
(plants)?: THEY USE QUADRANTS
1/8
,- mark off square areas of a set size, within a habitat using sticks and string, wood, plastic, or metal on ground.
- Count number of individuals within
- Multiple quadrat samples performed at several random locations
- Estimate population size and density within the entire habitat.
- Number and size of quadrat samples depends on type of organisms
8. How do population ecologists determine the size of mobile organisms (mam-
mals, birds, etc)?: Mark and recapture:
• Capture and mark a sample (first catch) (tags, labels, bands, paint, ..)
• Release back into environment to allow them to mix with rest of the population
• Collect a new sample and count it: n (second catch)
• From this second catch, count how many are marked x (out of second catch)
9. Total population size estimate FORMULA:: N= sn/x
N= # 1st catch(s) × Total # 2nd catch(n) / # marked in 2nd catch (x)
10. What types of distribution can a species have (hint: there are 3)? What
distribution do birds have, plants have, animals have?: uniform, random, clumped
11. What type of distribution is the most common?: clumped
2/8
, 12. What type of distribution results from interactions between individuals?: uni-
form
13. What type of distribution is independent from other individuals?: random
3/8
1. Populations are stable (TRUE OR FALSE): FALSE
2. study of the vital statistics of populations and how they change over time: de-
mography
3. Populations are a ....: dynamic entity (contains fluctuations, it changes)
4. What is DENSITY?: number of individuals per unit area or volume.
5. What is DISPERSION?: pattern of spacing among individuals within the population's boundaries
- how much they are spaced out
6. What are the 2 main things that is used to describe the population?: - Size (N):
total number of individuals
- Density: number of individuals within a specific area
7. How do population ecologists determine the size of immobile organisms
(plants)?: THEY USE QUADRANTS
1/8
,- mark off square areas of a set size, within a habitat using sticks and string, wood, plastic, or metal on ground.
- Count number of individuals within
- Multiple quadrat samples performed at several random locations
- Estimate population size and density within the entire habitat.
- Number and size of quadrat samples depends on type of organisms
8. How do population ecologists determine the size of mobile organisms (mam-
mals, birds, etc)?: Mark and recapture:
• Capture and mark a sample (first catch) (tags, labels, bands, paint, ..)
• Release back into environment to allow them to mix with rest of the population
• Collect a new sample and count it: n (second catch)
• From this second catch, count how many are marked x (out of second catch)
9. Total population size estimate FORMULA:: N= sn/x
N= # 1st catch(s) × Total # 2nd catch(n) / # marked in 2nd catch (x)
10. What types of distribution can a species have (hint: there are 3)? What
distribution do birds have, plants have, animals have?: uniform, random, clumped
11. What type of distribution is the most common?: clumped
2/8
, 12. What type of distribution results from interactions between individuals?: uni-
form
13. What type of distribution is independent from other individuals?: random
3/8
