Sigmoid growth curve, Biology

Assignment Help:

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


Related Discussions:- Sigmoid growth curve

What is quantitative techniques - microbial culture, What is Quantitative T...

What is Quantitative Techniques? Microbial quality of substances like food, milk, air, water, soil etc. can be assessed both qualitatively and quantitatively. Quantitative enum

Behavioural adjustments, Behavioural Adjustments When faced with a su...

Behavioural Adjustments When faced with a sudden temperature change, most animals make behavioural responses that enable them to avoid extreme or lethal conditions. Among the

Explain reversion flavor, Reversion flavor:  The rapid oxidation of br...

Reversion flavor:  The rapid oxidation of branched furan fatty acids on exposure to light, leads to the production of an intensive aromatic substance, which along with diacety

General process of post-hatching growth in insects, General process of post...

General process of post-hatching growth in insects While a young insect hatches out from an egg it is covered by a firm, inflexible, sclerotized cuticle, which because of its

Reproduction, name the sturcture formed when the male and female nuclei fus...

name the sturcture formed when the male and female nuclei fuse during fertilisation.

What is dietary management of tuberculosis, Dietary Management It must ...

Dietary Management It must be evident to you that majority of the tuberculosis patients are emancipated and malnourished. Proper dietary management it during and  after the inf

What do you mean by synapses, Q. What do you mean by synapses? Synapses...

Q. What do you mean by synapses? Synapses are the structures that transmit the neural impulse between two neurons. When the electric impulse arrives the presynaptic membrane

Grouping of stem cells-totipotent scs, Grouping of Stem Cells: The rang...

Grouping of Stem Cells: The range of differentiation “Potency” is an important property of Stem cells & serves as the basis for classifying cells as : Totipotent SCs -capa

Functional properties of cardiac muscle, Normal 0 false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd