Correct option is B
Explanation:
Resact is a sperm attractant protein found in certain marine organisms, such as sea urchins. It helps overcome the challenge of sperm and egg meeting in dilute environments by acting as a chemoattractant. Resact is released by eggs and creates a gradient in the surrounding environment, guiding sperm towards the eggs. This protein helps sperm find the egg even in the vast and diluted surroundings of the aquatic environment, making it crucial for successful fertilization in species with external fertilization.
Information Booster:
Resact helps in the chemotaxis of sperm towards the egg by creating a concentration gradient in the environment, increasing the chances of sperm meeting the egg.
The chemical signaling process, in which Resact acts as a chemoattractant, is vital for sperm to navigate through the water to reach the egg.
Resact is specific to species such as sea urchins, but similar mechanisms may be found in other marine organisms that rely on external fertilization.
The use of chemoattractants like Resact is an efficient way to overcome the challenge of dilution in external fertilization.
Additional Knowledge:
Bindin (option 1) is a protein that plays a role in the fusion of sperm and egg membranes in species such as sea urchins, but it does not help in overcoming the challenge of sperm-egg meeting in dilute environments.
Izumo (option 3) is a protein on the sperm surface involved in sperm-egg membrane fusion but is not related to overcoming the concentration challenge in external fertilization.
Ovastacin (option 4) is an egg enzyme that plays a role in blocking polyspermy (preventing multiple sperm from fertilizing the egg) and is not involved in sperm attraction.
