A reaction fo granules content which har...

A reaction fo granules content which harden the zona pellucida and ensures sure block to polyspermy is

acrosomal reaction

cortical reaction

acrosin reaction

binding reaction

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Immediately after the fusion of sperm and egg plasma membranes, the egg shows a cortical reaction. In this reaction . In this reaction, the cortical granules present beneath the egg's plama membrane fuse with the plama membrane and release enzymes between it and zona pellucida. These enzymes harden the zona pellucida, which now functions to block polyspermy.

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Assertion: Only one sperm can fertilise an ovum. Reason: During fertilisation, a sperm comes in contact with zona pellucida layer of the ovum and induces changes in the membrane that blocks the entry of additional sperms.

A block of mass m is placed on a rough inclined plane. The corfficient of friction between the block and the plane is mu and the inclination of the plane is theta .Initially theta=0 and the block will remain stationary on the plane. Now the inclination theta is gradually increased . The block presses theinclined plane with a force mgcostheta . So welding strength between the block and inclined is mumgcostheta , and the pulling forces is mgsintheta . As soon as the pulling force is greater than the welding strength, the welding breaks and the blocks starts sliding, the angle theta for which the block start sliding is called angle of repose (lamda) . During the contact, two contact forces are acting between the block and the inclined plane. The pressing reaction (Normal reaction) and the shear reaction (frictional force). The net contact force will be resultant of both. Answer the following questions based on above comprehension: Q. For what value of theta will the block slide on the inclined plane:

A block of mass m is placed on a rough inclined plane. The corfficient of friction between the block and the plane is mu and the inclination of the plane is theta .Initially theta=0 and the block will remain stationary on the plane. Now the inclination theta is gradually increased . The block presses theinclined plane with a force mgcostheta . So welding strength between the block and inclined is mumgcostheta , and the pulling forces is mgsintheta . As soon as the pulling force is greater than the welding strength, the welding breaks and the blocks starts sliding, the angle theta for which the block start sliding is called angle of repose (lamda) . During the contact, two contact forces are acting between the block and the inclined plane. The pressing reaction (Normal reaction) and the shear reaction (frictional force). The net contact force will be resultant of both. Answer the following questions based on above comprehension: Q. If mu=(3)/(4) then what will be frictional force (shear force) acting between the block and inclined plane when theta=30^@ :

A block of mass m is released from rest ffrom point A which rests on a semi circular groove as shown in the diagram. Find value of normal reaction between the vertical wall and the large block of mass M when m reaches at B.

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