Which process involves the fusion of male and female gametes resulting in the formation of a zygote?

Neurons communicate with each other through both electrical and chemical signals.

The electrical signal, or action potential, runs from the cell body area to the axon terminals, through a thin fibre called axon.

Neurons also communicate with one another at junctions called synapses. At a synapse, one neuron sends a message to a target neuron—another cell.

Most synapses are chemical; these synapses communicate using chemical messengers.

Choice A is incorrect because neurons communicate not only through electrical signals but also through chemical signals.

Choice B is incorrect because neurons communicate not only through chemical signals but also through electrical signals.

Choice D is incorrect because neurons do not communicate through mechanical signals.

Hydrogen bonds are responsible for the unique properties of water and play a crucial role in the structure of DNA and proteins.

Hydrogen bonds are weak electrostatic attractions between a hydrogen atom covalently bonded to an electronegative atom and another electronegative atom.

Choice B.

Covalent bonds is incorrect because covalent bonds are strong chemical bonds formed by the sharing of electrons between two atoms.

Choice C.

Ionic bonds is incorrect because ionic bonds are chemical bonds formed by the transfer of electrons from one atom to another, resulting in the formation of ions.

Choice D.

Van der Waals forces is incorrect because Van der Waals forces are weak intermolecular forces that arise from temporary dipoles induced in atoms or molecules.