IB Biology Topic C4.1.8 Modelling of the Sigmoid Population Growth Curve Revision Notes (SL/HL)

IB Biology Topic C4.1.8 Modelling of the Sigmoid Population Growth Curve Revision Notes (SL/HL) | RevisionDojo

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We Model the Sigmoid Curve by Growing Real Populations and Plotting Their Data

The sigmoid growth curve is a model of how a population changes over time in a habitat with limited resources.
We test the model by culturing fast-growing organisms, counting them at intervals, and comparing the data to the predicted S-shape.

The three phases (exponential, transitional, plateau) are described in C4.1.7; here the focus is modelling real data.

Note

In the exponential phase, resources are abundant and growth is rapid.
In the transitional phase, competition and other limiting factors slow growth.
In the plateau phase, the population levels off at the carrying capacity (K).

Duckweed Is an Easy Model for Tracking Population Growth

Duckweed (Lemna spp.) is a floating aquatic plant that reproduces quickly, so a whole growth curve appears within weeks.
Set up:
1. Fill a container with water and a nutrient solution, then add a few duckweed fronds.
Measure:

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Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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We Model the Sigmoid Curve by Growing Real Populations and Plotting Their Data

The sigmoid growth curve is a model of how a population changes over time in a habitat with limited resources.
We test the model by culturing fast-growing organisms, counting them at intervals, and comparing the data to the predicted S-shape.

The three phases (exponential, transitional, plateau) are described in C4.1.7; here the focus is modelling real data.

Note

In the exponential phase, resources are abundant and growth is rapid.
In the transitional phase, competition and other limiting factors slow growth.
In the plateau phase, the population levels off at the carrying capacity (K).

Duckweed Is an Easy Model for Tracking Population Growth

Duckweed (Lemna spp.) is a floating aquatic plant that reproduces quickly, so a whole growth curve appears within weeks.
Set up:
1. Fill a container with water and a nutrient solution, then add a few duckweed fronds.
Measure:

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic C4.1.8: Modelling of the Sigmoid Population Growth Curve Notes

We Model the Sigmoid Curve by Growing Real Populations and Plotting Their Data

Duckweed Is an Easy Model for Tracking Population Growth

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

We Model the Sigmoid Curve by Growing Real Populations and Plotting Their Data

Duckweed Is an Easy Model for Tracking Population Growth

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics