Events prior to the sperm-egg fusion, Biology

Events prior to the Sperm-Egg Fusion

In a number of organisms that have been studied, the sperm remain immotile in the testis or in the semen. The sperm become active and motile when they are close to the eggs. Several factors have been attributed for the activation of the sperm which include pH, oxygen tension, presence of certain ions etc. Detailed studies in sea urchin have shown a change in the pH as the cause for the activation of the sperm. In mammals the definite cause of activation is not known and it is presumed that sperm motility begins with the ejaculation of the semen into the female reproductive tract. Activation of the sperm does not ensure that the sperm will meet the egg. In instances where fertilization occurs outside the organism, i.e. external fertilization, chemotactic mechanisms have been evolved to attract the sperm towards the egg. In fish eggs substances found near the micropyle attract the sperm. The substances found near the micropyle make the sperm to move rapidly to the vicinity of the egg.

Posted Date: 1/25/2013 12:14:37 AM | Location : United States







Related Discussions:- Events prior to the sperm-egg fusion, Assignment Help, Ask Question on Events prior to the sperm-egg fusion, Get Answer, Expert's Help, Events prior to the sperm-egg fusion Discussions

Write discussion on Events prior to the sperm-egg fusion
Your posts are moderated
Related Questions
What is the function of the feet in molluscs? How is the mollusc foot related to the name given to the classes of the phylum? The mollusc foot has the function of locomotion, s

C a ttle and buffalo diseases Rinderpest: Rinderpest is the most destructive of the virus diseases of cloven-footed animals, viz. cattle, buffaloes, sheep, goats, pigs and

Explain Personal Risk Factors in CAD? The personal risk factors are the factors that are specific and characteristic for a particular individual and are non-modifiable in natur

Five Kingdom Classification Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Submerged implants Decision has to be made between two techniques. These techniques are: Technique 1: Stage two using a mucoperiosteal flap Technique 2: Stage two done wi

notochotr is absent in the group ...........

How many grams of sodium dodecyl sulfate (mw = 288.37) would you dissolve in 80 mLs of water to make a 20% solution of SDS?

Which of the following variations on translation would be most disadvantageous for a cell? A) translating polypeptides directly from DNA B) using fewer kinds of tRNA C) having only

Define respiration in animals

Pleural, Pericardial, and Ascitic fluid Collection:      The procedure is called paracentesis . If for pleural cavity is called thoracocentesis , and for pericardial cavity c