OBJECTIVE LIFE SCIENCE
DEVELOPMENTAL BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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an electric shock generated by the sperm entry
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release of Calcium ions stored in the cortex of the egg
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the sperm entering the egg and releasing an egg activator molecule
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the rotation of the cortex towards the sperm entry point
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Detailed explanation-1: -The redistribution of secretory granules is a preparative step for the cortical reaction (CR), a calcium-dependent exocytotic process. The trigger for the CR is the fusion of the sperm plasma membrane with the oolemma. This fertilization fusion activates a series of intracellular signaling pathways [3].
Detailed explanation-2: -In some vertebrate and invertebrate eggs, the so-called cortical reaction contributes to their activation and prevents polyspermy during fertilization. This process involves biogenesis, redistribution, and subsequent accumulation of cortical granules (CGs) at the female gamete cortex during oogenesis.
Detailed explanation-3: -In many animals (e.g., flies, worms, frogs, mice), fertilization triggers activation of the egg, whereas in others, including zebrafish, contact of the egg with spawning media (e.g., water) stimulates the egg to activate development.