Sigmoid growth curve, Biology

GROWTH CURVES -

S-shaped or sigmoid -

Described by Verhuhst in 1839.

It shows 5 phases -

(i) Lag phase

(ii) Positive acceleration phase

(iii) Exponential phase

(iv) Negetive accesleration phase

(v) Stationary

1480_sigmoid growth curve.png

1.       Lag phase -

  • Early stage of curve.
  • When new individuals come in new environment so minimum growth occur in these phase.
  • It is due to absence of new resources.
  • It is due to lack of adaptations.

2.       Positive acceleration phase -

  • Growth rate is increased.
  • Birth rate increases.
  • Death rate is minimum.

3.       Exponential phase -

  • Individuals become adaptated.
  • Rapid growth occur.
  • Birth rate very high.
  • Death rate very low.

4.       Negetive accesleration phase -

  • Growth rate decreases.
  • Available sources become limited.

5.       Stationary -

  • Resources are limited.
  • Birth rate is equal to death rate.
  • So growth rate is zero.
  • In the growth curve of bacteria after stationary phase growth decreases due to unavailability of resources.

2258_sigmoid growth curve1.png

If semi log curve is drawn for bacteria curve is in the form of straight line.

897_sigmoid growth curve2.png

Posted Date: 10/4/2012 7:20:35 AM | Location : United States







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

Write discussion on Sigmoid growth curve
Your posts are moderated
Related Questions
Why is not Mendel's second law always valid for two or more phenotypical traits of an individual? The Mendel's second law, or the law of the independent assortment, is valid fo

Determine the Benedict's Test Glucose in urine is detected by Benedict's method and the test is known as Benedict's test. This test is used to detect glucose in urine (Glycosur


Equipment : To maintain effective circulation and carry out functions of the lungs during an open heart operation the equipment should have: 1) Blood Pump 2) Oxygenator 3

Characteristic Features of Phylum Arthropoda Well-developed muscular system along with striated muscles attached to the exoskeleton, and visceral organs having smoot

Explain about the Derived Proteins? These are not naturally taking place proteins and are obtained from simple proteins by the action of enzymes and chemical agents, heat, mech

Q Sponge identity card. How are sponges characterized according to example of representing beings, basic morphology, type of symmetry, embryonic (germ) layers and coelom, digestive

a - HELIX In this intra molecular hydrogen bonds are present The polypeptide chain is spirally coiled, generally in a clock-wise or right handed fashion. Glycine


Pantothenic acid (Calcium pantothenate) Calcium pantothenate is a white, loose, faintly hygroscopic powder without odour and of bitter taste. It is easily soluble in water, gly