Theory of embryology - pre-formation theory, Biology

Assignment Help:

PRE FORMATION THEORY -

Proposed by Marcello Malpighi.
Studied chick egg and proposed his work in "De ova-incubato".
According this different part of embryo previously present in the eggs. These parts developed through the growth.
Swammerdam proposed that the sex cell contain preformed emrbyo or a more or a less perfect miniature of the adult.
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.
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

Gum conditions failure to remove plaque, What gum conditions may result fro...

What gum conditions may result from a failure to remove plaque? Gingivitis (gum inflammation) and periodontal disease (infection of the socket) might be result from a failure t

Dreams, what do our brain and heart do when we are asleep?

what do our brain and heart do when we are asleep?

Explain fixer1 split s in second heart, Explain Fixer1 Split S in second he...

Explain Fixer1 Split S in second heart ? A2P2 interval is wide and persistent and doesn't change during respiratory cycle. It is an auscultatory hallmark of uncomplicated ostiu

Classification of plant on the basis of their resemblances, Q. Classificati...

Q. Classification of plant on the basis of their resemblances? Pliny seemed to have little interest in the classification of plant on the basis of their resemblances. He classi

Can you define termination of the stress test, Q. Can you define terminatio...

Q. Can you define termination of the stress Test? Test should be terminated when: 1) PVCS develop in pairs or with increasing frequency or when ventricular tachycardia devel

Mitochondria , MITOCHONDRIA It is the power house of the cell becaus...

MITOCHONDRIA It is the power house of the cell because they are the major centers of release of energy in the aerobic respiration. Mitochondria and chloroplast both are a

Determine the procedure of rothera test, Rothera's Test It is highly se...

Rothera's Test It is highly sensitive for both acetoacetic and acetone. Although it is one of the oldest methods still it is widely used. Procedure: - Take about 5ml of

Cold chain system, Cold Chain System Vaccines are sensitive to heat. ...

Cold Chain System Vaccines are sensitive to heat. On exposure to heat their potency is lost. Once a vaccine has lost its potency it cannot be regained, so it is important

Explain the ethological approach in taxonomy, Explain the Ethological Appro...

Explain the Ethological Approach in Taxonomy The use of behavioural or ethoIogica1 characteristics in animals is relatively new, though extremely useful, particularly in the id

Contractility, Myocardial contractility is mostly dependent on the level of...

Myocardial contractility is mostly dependent on the level of sympathetic nerve activity and is also increased by circulating catecholamines and inotropic drugs like dopamine and do

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages