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 gastrulation? How during gastrulation are the first two germ layers formed? What are these germ layers? Gastrulation is the process by which a portion of the blastula w

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Modern Theory Naturalistic theory: According to this theory Life originated upon our earth spontaneously from nonliving matter. But there are two significant points in this r

What is the life cycle of the gymnosperms? As all plants they show a diplobiontic life cycle, i.e., alternation of generations with diploid and haploid stages. The lasting (fin

Removable soft tissue-borne partial dentures have one of the lowest patient acceptance rates in dentistry. Those patients wearing the partial dentures often exhibit greater mobilit

a) Which region of the retina gives the most accurate interpretation of the image? b) What type of light-sensitive cell is present in this region?   (a) The fove

Define Initial Phase for nutritional treatment of neuro trauma patients? In this, the life threatening conditions need to be controlled first.  Soon the nutritional support mu

What is the phenotype? Phenotype is every observable characteristic of a living being conditioned by its genes. A few phenotypes may be altered by nongenetic factors (for insta

Following statement true for prokaryotic or eukaryotic? They use deoxyribonucleic acid as their major information storage molecule

Are the following statements true for eukaryotes , prokaryotes, both groups, or neither group? Answer They use a deoxyribonucleoside triphosphate as their energy currency"D They us