How are sea urchin sperm able to locate eggs even though both types of gametes are released into a potentially large surrounding body of water, such as the open ocean?
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a
Using chemotactic agents released by sperm to bind to eggs
b
By the ability of mature sea urchins to sense and approach others prior to gamete release
c
By sensing appropriate currents
d
Using sperm-activating peptides
a
Using chemotactic agents released by sperm to bind to eggs
a
Using chemotactic agents released by sperm to bind to eggs
The correct answer is a) Using chemotactic agents released by sperm to bind to eggs.
Sea urchins have a fascinating mechanism that allows sperm to locate eggs even in a vast body of water. The sperm releases chemotactic agents, which are chemical signals that can attract or repel other cells. In this case, the chemotactic agents released by the sperm attract and bind to molecules on the surface of the eggs.
To understand how this works, scientists have studied the molecules on the surface of the eggs that act as receptors for the chemotactic agents. These receptors are specifically designed to bind to the chemotactic agents released by the sperm. When the chemotactic agents and the receptors on the egg surface bind together, they create a signaling cascade that allows the sperm to swim in the right direction towards the egg.
It's important to note that the chemotactic agents are released in response to a chemical gradient. The eggs release chemical signals that create a concentration gradient in the surrounding water. As the sperm swims through the water, it detects the changing concentration of these chemical signals and follows the gradient towards the eggs.
This remarkable ability of sea urchin sperm to locate eggs using chemotactic agents is just one example of how organisms have evolved different reproductive strategies to ensure successful fertilization. By releasing these chemical signals and responding to them, sea urchin sperm can increase their chances of finding and fertilizing eggs even in a large body of water like the open ocean.