Theory of embryology - pre-formation theory, Biology

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

Posted Date: 10/3/2012 6:47:58 AM | Location : United States







Related Discussions:- Theory of embryology - pre-formation theory, Assignment Help, Ask Question on Theory of embryology - pre-formation theory, Get Answer, Expert's Help, Theory of embryology - pre-formation theory Discussions

Write discussion on Theory of embryology - pre-formation theory
Your posts are moderated
Related Questions
OESTROU S CYCLE - Also known as heat period. Common in rabbit, cat, dog, sheeps. In this period desire for copulation occur. Possibility of fertilization is 100%.

Packaging for instruments and cassettes Packaging used for instruments and cassettes prior to sterilization includes wrap, paper pouches, plastic pouches, combination paper/pl

How can brain research improve the treatment of pain? Despite recent advances in understanding how brain processes and responds to pain, experts say pain continues to be grossl

Q. What Treatment should be used for cardiac tamponade? Percutaneous Pericardiocentesis Cardiac tamponade is an acute emergency and percutaneous pericardiocentesis must b

Q. How different are fecundation in chondrichthyes and in osteichthyes? In chondrichthyes fecundation is internal by resources of copulation. In osteichthyes fecundation genera

Define Functional Role of Sugars in Food? From the consumer's point of view, sugars are basically related with sweetness. Sweetness is essentially a physiological sensation. Th

PEROXISOMES AND GLYOXYSOMES Certain small ovoid  unit membrane bound  sac like  cytoplasmic  organelles, resembling  lysosomes in size  and appearance  were  isolated  from var

Are protozoans under the Kingdom Animalia?

Are proteins with the same number of each different amino acid that form them necessarily identical proteins? Even if many proteins have the similar number of each dissimilar a

Explain soybean protein The need for the development of soybean protein concentrates stemmed primarily from two considerations: to enhance protein concentration and to improve