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
How to Planning the Daily Diet for Underweight Patients? As mentioned above you need to add calories gradually to the diet. A practical way of doing so is to take the present i

On a given microscope, the numerical aperture of the objective is 1.5. The microscope is provided with a filter that selects a wavelength of 500 nm. What is the limit of resolution

Q. Antioxidants and Flavanoids requirement in dyslipidemia? Antioxidants and Flavanoids: You must have already read about different antioxidants present in our foods. The body

Male reproductive disorders due to infections Septicemic infections have a greater affinity for vesicular glands than other regions of the reproductive tract viz. prostate, am

Phylum Zygomycetes 1) Asexual reproduction by non-motile spores produced from a stalked spore case which is known as sporangium. 2) They reproduced by- conjugation between n

Algae Advantages a) Produces proteins which have almost all the Essential Amino acids. b) Rich in tyrosine and serine, low in sulphur containing amino acids.

Define Sample Titration for Fehling Soxhlet Method Dilute the given sample glucose solution in 100 ml volumetric flask to the mark with distilled water. Pipette 5 ml of Fehling

Q. Explain about Diabetes Mellitus? Diabetes Mellitus is a metabolic disorder characterized by chronic hyperglycemia (increased sugar) with disturbances of carbohydrates, fats

Define Primary Level Care - Public Nutrition? This is the first level of contact of an individual, the family and the community with the national health system. It is possible

Determine the Types of Foods used in space? Weight and volume have always been the primary design factors for every piece of hardware launched into space. The shuttle is no exc