Population growth curve, Biology

Increase in population size is known as population growth. It depends upon number of persons added to the population and number of persons lost from the population. Addition in population occurs by birth or immigration. Loss in population occurs by death or emigration. If more persons are added than lost, the population will show positive growth. If more persons are lost than added, the population will show negative growth. If addition and loss are balanced, the population will become stationary or show zero growth.

Population growth curve:

            These are curves which show growth (positive or negative) in population. A graph is made by plotting number of individuals against time.

            These are of two types:

(i)                 J-shaped growth curve

(ii)               S-shaped growth curve

 

(i)     J-shaped growth curve:

It has two phases, lag phases and exponential phase. In lag phase, the growth curve shows little or no increase in population, where as in exponential phase population multiply rapidly in an unrestricted manner. This type of growth is only possible in laboratory where conditions for growth are provided.

(ii)         S-shaped or sigmoid growth curve:

It has three phases-lag phase, exponential phase and stationary phase. It shows little growth in lag phases, rapid in exponential and stable or balanced growth in stationary phases. The upper level beyond which no major increase in growth occurs is also called as carrying capacity (K). Carrying capacity is the environment's ability to provide necessary resources to support population. It is also known as logistic pattern of growth.

Posted Date: 7/11/2012 7:44:53 AM | Location : United States







Related Discussions:- Population growth curve, Assignment Help, Ask Question on Population growth curve, Get Answer, Expert's Help, Population growth curve Discussions

Write discussion on Population growth curve
Your posts are moderated
Related Questions
Enzymatic analysis in foods: applications in food industry Did you know that the degree of bacterial contamination of foods or freshness of food, particularly, meat etc. can be

What evidence did Charles Elton collect that suggested that fluctuations in hare and lynx populations were related? What other evidence shows that these fluctuations ma

Which one of the following statements is correct with respect to AIDS? 1. The HIV can be transmitted through eating food together with an infected person 2. Drug addicts are

Which of the following is a true statement regarding the Eyes Absent Protein? A. EYA is a transcriptional activator that having both a DNA binding domain and a transactivation

Virus envelope is known as: 1.  Capsid 2.  Virion 3.  Nucleoprotein 4.  Core Capsid

What is a biome? A biome is a prevailing ecosystem constituted by same biotic and abiotic factors present in one or more regions of the planet.

Explain about common congenital heart diseases ? Congenital Heart Disease is commonly classified as acyanotic and cyanotic. Acyanotic Left to right shunts Obstructive Lesion

True or false, adaptations are the result of finding the best or only solution to a given problem a species faces.

Darwin put fort the notion of the survival of the fittest. How do we define 'fittest'? The answer usually given is those who survive. So you can readily see that this is a circular

Q. What is the significance of magnesium for plants? What are the other major biological functions of magnesium? Magnesium is basically vital for plants because it is part of t