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

Define class – arachnida, Define Class – Arachnida? The class Arachnida (...

Define Class – Arachnida? The class Arachnida (Arachnida = spider) has terrestrial and few aquatic animals. It includes spider, scorpions and mites. 1. Prosoma bears. six pair

Vitamin - k, VITAMIN - K Also known as naptho quionone / anti haemo...

VITAMIN - K Also known as naptho quionone / anti haemorrhagic vitamin / coagulation vitamin / menadone . It requires for formation of blood clotting factor prothrombin.

Show clinical symptoms of galactosemia, Q. Show Clinical symptoms of galact...

Q. Show Clinical symptoms of galactosemia? Clinical symptoms of galactosemia deficiency is found to appear early in infancy. Some infants are born with cataract, jaundice and

Describe fourth heart sound in details, Describe Fourth Heart Sound in deta...

Describe Fourth Heart Sound in details? S 4 is generated during the atrial-filling phase. It is a low frequency event. LVS, is best heard over apex. Mechanism of S 4 generat

Which are the beings that form the kingdom animalia, Which are the beings t...

Which are the beings that form the kingdom Animalia? What are the two big groups into which this kingdom is divided? The kingdom Animalia is the animal kingdom. Commonly the ki

How are animals classified according to the germ layers, Q. How are animals...

Q. How are animals classified according to the germ layers present in their embryonic development? Cnidarians are diploblastic, that is they present only ectoderm and endoderm.

EMBRYONIC PERIOD, LIST OUT THE DERIVATIVES OF 3 GERMS LAYER-ectoderm, meso...

LIST OUT THE DERIVATIVES OF 3 GERMS LAYER-ectoderm, mesoderm and endoderm

What are anticoagulants, Q. What are anticoagulants? What are the practical...

Q. What are anticoagulants? What are the practical applications of anticoagulants, like heparin, in Medicine? Ordinarily there are anticoagulants circulating in the plasma sinc

What are vectors of parasites, Q. What are vectors of parasites? The Ve...

Q. What are vectors of parasites? The Vectors of a parasite are organisms can transport the parasite during stages of its life cycle mediating the infection of other hosts. For

Explain spray-dried milk powder, Q. Explain Spray-dried milk powder? Th...

Q. Explain Spray-dried milk powder? The milk which is concentrated by the process of spray drying contains about 40- 45% total solids. Do you know how the dried milk powder i

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