Question

A population of Paramoecium caudatum was grown in a culture medium. After 5 days the culture medium became overcrowed with Paramoeium and had depleted nutrients. What will happen to the population and what type of growth curve will the population attain? Draw the growth curve.

Answer 1

As the population of Paramoecium caudatum was grown in a culture medium. After 5 days the culture medium became overcrowded with Paramoeium and had depleted nutrients because after the overcrowding of paramoecium the nutrients became limited and got depleted.

Sigmoid type of growth curve would be obtained. This shows a population growing in a habitat having limited resources.

The graph obtained is shown below:

                         Logistic growth curve

1. The graph shows an initial lag phase. After that, an increase in population takes place due to the availability of nutrients also known as acceleration. Following this deceleration takes place as the available nutrients got depleted because of excessive usage and growth of paramoecium stops. At last, asymptote occurs.
2. When the population reaches carrying capacity. A plot is formed showing the sigmoid curve.
3. This type of growth is known as Verhulst-Pearl logistic growth.
4. This is represented by an equation: dN/dT = rN(K - N/K)

          dN/dT = rN(1 - N/K)

          Here, (1 - N/K) is environmental resistance