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

Explain bond specificity, Bond specificity Some  enzymes  act  on  a pa...

Bond specificity Some  enzymes  act  on  a particular  bond  (glycosidic,  peptide,  ester  etc.). Examples:  pepsin,  trypsin,  chymotrypsin  etc. are  all  only  acting  on

What are the stages into which photosynthesis is divided, What are the stag...

What are the stages into which photosynthesis is divided? Photosynthesis is separated into the photochemical stage, or light reactions, and the chemical stage. Photosynthesi

What is the optimum temperature for catalyses, What is the optimum temperat...

What is the optimum temperature for catalyses? For any chemical reaction, the reaction rate enhances with temperature, so the higher the temperature, the faster the rate. For a

Shapes - types of nursing units, Shapes: Nightingale Ward  In the 1...

Shapes: Nightingale Ward  In the 1940s,  this traditional nursing unit was based on  the long rectangle pavilion type ward and self-contained unit. This concept is establis

Protection of protein meals or bypass protein, Protection of protein meals ...

Protection of protein meals or bypass protein The protein of oil cakes, having higher protein degradability, such as groundnut cake, mustard cake are utilized in the rumen les

Meiosis, Why is it necessary to have the second division in meiosis even th...

Why is it necessary to have the second division in meiosis even though cells have already been reduced to haploid number after the first division?

Plant water, Plant Water Role of Water in Plants You know that water i...

Plant Water Role of Water in Plants You know that water is the main constituent of plant cells. It performs the following major functions Water as a Solvent Water is a v

Agro industrial-selenium, Selenium Glutathione peroxidase (GSH-Px) was...

Selenium Glutathione peroxidase (GSH-Px) was the first selenium metalloenzyme identified.Glutathione peroxidase catalyzes the reduction of hydrogen peroxide and lipid h yp r o

Knocking and octane number, Mixture of gasoline and air is used as fuel in ...

Mixture of gasoline and air is used as fuel in internal combustion engine. It is highly compressed and then ignited. 1.      The process involves four strokes : 2.      The f

Determine the categories of sleep disorders, Determine the categories of sl...

Determine the categories of sleep disorders Sleep disorders are generally divided into two major groups: 1) Narcolepsy, which is characterised by excessive sleep or brief in

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