Preformation theory - pre-mendelian theory, Biology

Preformation Theory (1632-1723)

(i)         Scientist 'Malpighi Swammerdam' propounded the preformation theory. This theory holds that the sex cells (sperm and ova) had the miniature copy of adults and the development of embryo was actually only the enlargement of parts that were already present in the sperm or egg.

(ii)         This miniature form of the animal present in the gamete was called 'Homunculus'.

(iii)        This theory was supported by Hartsoeker.

(iv)        Those who considered homunculus to be present is sperms were called Spermist.

(v)         Leeuwenhoek & Hartsoeker believed that miniature of organism was present in the head of the sperm.

(vi)        Those who considered homunculus to be present in ova (eggs) were called Ovist.

(vii)        The term preformation covers the both.

(viii)       Malpighi, Swammerdam & Bonnet believed that miniature organism was present in the egg.

Posted Date: 10/10/2012 3:19:39 AM | Location : United States







Related Discussions:- Preformation theory - pre-mendelian theory, Assignment Help, Ask Question on Preformation theory - pre-mendelian theory, Get Answer, Expert's Help, Preformation theory - pre-mendelian theory Discussions

Write discussion on Preformation theory - pre-mendelian theory
Your posts are moderated
Related Questions
Q. What is Intermediate acting insulin? Intermediate acting: This type works more slowly than short acting. It works hardest 8-12 hours after injection and still keeps on worki

During a routine annual physical,a patient was checked to determine the amount of glucose in the blood.After the assay,It was found that the glucose that the glucose concentration

Chemical Weathering The rocks while getting disintegrated may also undergo chemical change. Water is an important agent in bringing about chemical changes due to dissolution or

List out the endothermic and exothermic reactions taking place in our body

List a few important uses of food hydrocolloids. A few important uses of food hydrocolloids are: to increase viscosity and to stabilize food products. Its other uses  include u

Q. How is the striped pattern of the striated muscle cells formed? The functional units of the muscle fibers are the sarcomeres within the sarcomeres blocks of myosin and actin

What proportion of children with Down syndrome do you expect when women with down syndrome have children with men who have 46 chromosomes? Justify answer

Which is true of the resting membrane potential? A. It requires few ions to be distributed unevenly. B. It has the same value in all cells C. Only nerve and muscle cells h

Explain the Treatment Options after Endodontic Failure a) Non-surgical retreatment "re-endo", b) Root-end surgery "if there is a will detected mistake as separated instrumen

Eutrophication - Effect on Water Bodies Moderate quantities of sewage decay naturally in a water body and water gets purified after some time. But the problem arises when the