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

Golgi apparatus, GOLGI  APPARATUS It is a complex cyctoplasmic stru...

GOLGI  APPARATUS It is a complex cyctoplasmic structure made up of smooth membrane saccules or cisternae, a network of tubules with vessicles and vacuoles, which take part i

Fowl spirochaetosis, Fowl spirochaetosis The causal agent Borrelia anse...

Fowl spirochaetosis The causal agent Borrelia anserina is a spiral-shaped organism about 8-30 um in length but commonly 14-15 um long and 0-3 um wide. The organisms are activel

Method of cloning dna fragments into plasmids, During our discussion of rep...

During our discussion of replication origins we took a step-by-step look at the method of cloning DNA fragments into plasmids . Based on your knowledge of this discussion which

Cartoon, A dialogue and cartoon between haemoglobin and chlorophyll

A dialogue and cartoon between haemoglobin and chlorophyll

Classification of fishes, Q What are the two major classes into which fishe...

Q What are the two major classes into which fishes are divided? Ans. Fishes are divided into two major classes: osteichthyes, bony fishes (tuna, sardines, salmons) , and chondr

Biologyical problem, Ask question #Minimum 100 hhejejhjehjwords accepted#

Ask question #Minimum 100 hhejejhjehjwords accepted#

Explain adverse effects of indinavir, Explain Adverse effects of Indinavir ...

Explain Adverse effects of Indinavir   In addition to adverse effects similar to those of other protease inhibitors, indinavir causes elevation of indirect bilirubin, indinavir

Animal around us, #question.what are the reason that arthropodans are abund...

#question.what are the reason that arthropodans are abundant in nature.

What is the function of the feet in molluscs, What is the function of the f...

What is the function of the feet in molluscs? How is the mollusc foot related to the name given to the classes of the phylum? The mollusc foot has the function of locomotion, s

Define iron deficiency anaemia during pregnancy, Define Iron deficiency ana...

Define Iron deficiency anaemia During pregnancy? Iron deficiency anaemia (microcytic hypo chromic anaemia) is widespread among adolescents and young women during their reproduc

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