Cette leçon contient 22 diapositives, avec quiz interactifs et diapositives de texte.
La durée de la leçon est: 30 min
Éléments de cette leçon
EES_Y3_LSN3A
Evolution, Ecology & Sustainability
Slide 1 - Diapositive
Population size
immigration
emigration
death
birth
Slide 2 - Question de remorquage
Population growth
Involves:
Biotic potential: max reproduction rate given all the resources the population needs
Environmental resistance: all factors that may limit growth. (scarcity of resources, predation, climate conditions etc)
Carrying capacity: max population size that can be supported by a particular environment
Slide 3 - Diapositive
Population curves
J-curve: often seen in fast reproducing organisms that colonise a new environment. Exponential growth followed by hitting a limiting factor and often the population crashes
S-curve: Exponential growth until population hits environmental resistance and stabilises around the carrying capacity
Slide 4 - Diapositive
Carrying capacity
Environmental resistance
Few reproducing individuals
Exponential growth
Slide 5 - Question de remorquage
What is population density?
Slide 6 - Question ouverte
Environmental resistance
Can be:
Density indepent: these factors influence all organism in a population irrespective of population density. Can be biotic of abiotic
Density dependent: the influence of these factors on population size depend on the density of the population. Usually the higher the density the bigger the impact of these factors. Always biotic
Slide 7 - Diapositive
What is a square called that we use to sample populations?
A
grid
B
quadrat
C
cube
D
quarter
Slide 8 - Quiz
These four 1m2 squared quadrats were place in a 8m2 garden. Estimate the total population of flowers in the whole garden.
A
16
B
8
C
40
D
20
Slide 9 - Quiz
Which one of these is a correct assumption you need to make about a population between samplings?
A
It is a closed population
B
It won't rain between samplings
C
There are lots of deaths
D
There are lots of births
Slide 10 - Quiz
If 50 crabs were captured and marked and then released and then a few days later 25 were caught and of those 5 were marked. What would the estimate of the population be?
A
500
B
250
C
75
D
200
Slide 11 - Quiz
An area of 5m2 was sampled using a quadrat to find a total of 10 sunflowers. If the area of the field was 200m2 , what is the estimated number of sunflowers in the field?
A
20
B
40
C
400
D
2000
Slide 12 - Quiz
A factor that would increase the size of the population
A
Emmigration
B
Death Rate higher than Birth Rate
C
Birth Rate Higher than Death Rate
D
Drought
Slide 13 - Quiz
A factor that is more likely to affect crowded population much more than spread out population
A
Density dependent factor
B
Limiting factor
C
Natural disaster
D
Density independent factor
Slide 14 - Quiz
A factor that decreases the population or keeps it from increasing
A
Limiting factor
B
Food surplus
C
High birth rate
D
Carrying capacity
Slide 15 - Quiz
Example of a density independent factor
A
Natural Disaster
B
Disease
C
Resource Availability/Competition
D
Predators
Slide 16 - Quiz
What is the carrying capacity of the following graph?