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

Eye muscles, MUSCLES - In eye orbit, eye ball is fixed by 6 skeletal...

MUSCLES - In eye orbit, eye ball is fixed by 6 skeletal muscles attached to 3rd, 4th & 6th cranial nerves (motor). 4 - straight or recti muscles are present. 2 - oblique

Implantation, IMPLAN TA TIO N - Attachement of blastocyst on the ...

IMPLAN TA TIO N - Attachement of blastocyst on the endometrium of the uterus is called implantation. Generally it occurs 7th day after fertilisation. (6-10 days). Blas

What are the chemical substances formed by water photolysis, What are the c...

What are the chemical substances formed by water photolysis? What is the destination of each of those substances? Free electrons, hydrogen ions and molecular oxygen are liberat

Why plant cycle know as alternation of generations, Q. Why is the plant lif...

Q. Why is the plant life cycle known as alternation of generations? The plant life cycle is called as alternation of generations because in this cycle there are two different f

Digestive system of an arthropod, how does the digestive system of an arthr...

how does the digestive system of an arthropod operate

How to grow root hairs, How to grow root hairs Hairs can simply be seen...

How to grow root hairs Hairs can simply be seen on the roots of mustard seed grown on a damp flannel. Seeds placed on an earthenware dish standing in a soup plate having water

Explain micafungin sodium, Explain Micafungin sodium Micafungin sodium ...

Explain Micafungin sodium Micafungin sodium (Mycamine - Astellas), the second echinocandin antifungal1 to become available in the US, has been approved by the FDA for intraveno

Do protozoans have asexual or sexual reproduction, Q. Do protozoans have as...

Q. Do protozoans have asexual or sexual reproduction ? In protozoans reproduction is asexual or sexual. The most frequent form of sexual reproduction is binary scissiparity or d

Choice of transgenic animal, C h oice of transgenic animal First and ...

C h oice of transgenic animal First and foremost is the selection of animal species in which gene of interest is to be transferred. Whatever is the goal of production of tran

Endosperm with micropylar and chalazal haustoria, Endosperm with Micropylar...

Endosperm with Micropylar and Chalazal Haustoria Some plants develop haustoria from both micropylar and chalazal ends of endosperm. In Nemophila aggressive haustoria arise fr

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