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
Teleology : It is the study of interpretations of structures in terms of utility and purpose. Teleology is philosophical account that holds the final causes exist in nature, meanin

Pneumothorax Entry of air in the pleural cavity is called pneumothorax. It may be spontaneous, result of penetrating or non-penetrating injuries. Closed Pneumothorax

What is the neurotransmitter of the neuromuscular junction? How does the nervous system trigger muscle contraction? The nervous cells that trigger the muscle contraction are th

exoskeleton of peacock

Explain about the Magnesium - macro minerals? Magnesium (Mg) ranks fourth in overall abundance in body among the cations. It is also the least abundant among macro minerals, th

In mountain rabbits, the EL-1 gene is located on chromosome 3. Seven alleles of this gene have been identified in the population. With respect to EL-1, what is the maximum number o

What is the process of Breathing? Oxygen is supplied to the blood, and carbon dioxide is removed from the blood by the process known as breathing. Air is moved into an exchan

Linkage of Health With Development Health, in its comprehensive or holistic sense, refers to the state of completephysical, mental, social and spiritual well being of a person.

Define Regulation of amino acid levels in the blood? Regulation of amino acid levels in the blood: Vitamin D helps to prevent lossĀ  of amino acids through the kidney and thus

Define the Over nutrition obesity of Infant? An infant is never put on a reducing diet. The chances of obesity are least if an infant is exclusively breast-fed till 6 months. I