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 transgenic food? Transgenic beings are animals, microorganisms and plants that have recombinant DNA, i.e., genes from other plants, microorganisms or animals artificial

Define Vitamins required for underweight - nutritional care? If the diet provides good amounts of fresh fruits and vegetables, vitamin or mineral supplements are usually not re

Why is there a sense of pressure change inside the ear when someone goes down a mountain? The pressure inside the middle ear is keeps equal to the external ear (so to the exter

When the Balance Sheet column totals don't agree on the first attempt work backward through the process used in preparing the work sheet exclusively take the following steps until

Blood Pump :  Ideal Characteristics 1) I should be able to pump up to seven litres of blood per minute. 2) It should not damage cellular and cellular components of blo

Q. What is the kind of life cycle present in pteridophytes? Like all plants pteridophytes present diplobiontic (alternation of metagenesis or generations,) life cycle.

Segregation and Treatment of Dressing Waste In many departments waste is less and normally they do not have treatment facility for the bio-medical waste. In their case, interme

what two gases are released by animals during the process of cellular respiration

Based on your reading of the article "Origin of Life on Earth" which of the following is a false statement regarding how life developed? A. As proteins are needed for the repli

Expressed sequence tag (EST) is the short part of DNA sequence of corresponding to the fragment of the complementary DNA (made from the cell's messenger RNA). ESTs have been taken