Theory of embryology - pre-formation theory, Biology

Assignment Help:

PRE FORMATION THEORY -

  1. Proposed by Marcello Malpighi.
  2. Studied chick egg and proposed his work in "De ova-incubato".
  3. According this different part of embryo previously present in the eggs. These parts developed through the growth.
  4. Swammerdam proposed that the sex cell contain preformed emrbyo or a more or a less perfect miniature of the adult.
  5. Ovists view - This theory was supported by Malpighi, Spallanzani, Haller, Bonnet and swammerdam. These scientists belived that miniature organism was present in the eggs were called ovist.
  6. Spermist view - Leeuwenhoek and Hartsoeker believed that miniature of organism was present in the head of sperm. This miniature is called hommunculus in man and animalcule in other animals.

1978_miniature of sperm.png

Miniature in Mammalian Sperm


Related Discussions:- Theory of embryology - pre-formation theory

Aeration, Aeration A well-aerated soil is one in which gases are availa...

Aeration A well-aerated soil is one in which gases are available to plant roots and other soil organisms, in sufficient quantities and in proper proportions to support their no

Determine the symptoms of bacillus cereus, Determine the Symptoms of bacill...

Determine the Symptoms of bacillus cereus Extremely large numbers (10 8 per gram) of viable cells of B. cereus must be ingested to develop signs and symptoms of the syndrome.

Determine the diet chart for adolescents, Determine the Diet chart for Adol...

Determine the Diet chart for Adolescents? For adolescents, other than points covered above, there are two more important points of considerations. Inanition Fad diets

How age factors affect the requirement of protein, How age factors affect t...

How age factors affect the requirement of protein? Age: Protein in excess of maintenance needs is required, when a new tissue is being fornled. Certain age periods, when growth

Define st elevation in avr, Q. Define ST Elevation in aVR? Lead aVR oft...

Q. Define ST Elevation in aVR? Lead aVR often develops ST elevation as a reciprocal of ST depression in lead V2 to V6 or leads 2 and 3. It may occasionally show ST elevation in

Explain clinical manifestations of cardiomyopathy, Q. Explain Clinical Mani...

Q. Explain Clinical Manifestations of cardiomyopathy? 1) Asymptomatic, when the diagnosis is made by 2D Echocardiography. 2) Enlargement of LV. Apex is shifted down and out.

What are main successful vaccines, Main successful vaccines are live attenu...

Main successful vaccines are live attenuated and heat killed vaccines.

Importance of behaviour change communication, Importance of Behaviour Chang...

Importance of Behaviour Change Communication BCC is an in built part of a diabetes prevention, care and support program. Importance of BCC: · Increase knowledge. BCC can en

Is there a exchange of cells between the mother, Is there a exchange of cel...

Is there a exchange of cells between the mother and the fetus through the placenta? Under normal conditions, there is not a passage of cells across the placenta during gestati

State the copious sterile saline irrigation, Using copious sterile saline i...

Using copious sterile saline irrigation This can be delivered from a sterile infusion bag in a pressure cuff or a peristaltic pump. The drills can be adequately cooled by spray

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