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
Q. Number of risk factors of gout? A number of risk factors are related to the development of hyperuricemia and gout. These factors include: • Hereditary: Genetics may play

An account of characters of mollusca

What are the blood types of the ABO blood system? The type A, the type B, the type AB and the type O are the blood types of the ABO blood system..

Financing of Healthcare - Constraints One of the major constraints to improve the healthcare delivery system in developing countries is weak public sector management. These ec

Wildlife has influenced language, art, religion and social customs of many societies worldwide, and wild animals figure prominently in many cultures even today. In all cultures of

In the RBC, glucose can be oxidized to two primary products. One of the oxidation proucts is ribulose 5 phosphate, and the other is which of the following compounds? -lactate

Cell-mediated immunity:  The immune reaction directed against the body cells which have been infected by viruses and bacteria; and are controlled by T cells.

What is Fermentation ? Fermentation is a process used by anaerobic organisms and certain cells of aerobic organisms, such as muscle cells deprived of oxygen, to obtain addition

Q. According to the function of the transmitted neural impulse which are the types of neurons? How different are the concepts of afference and efference of the neural impulse trans

Which are the glands present in the epidermis of mammals, birds and reptiles? In the epidermis of birds and reptiles there are almost no glands. In mammals there are sweat glan