Synapses in which gap junctions allow ions to diffuse quickly from cell to cell are called synapses.

electrical synapse

Explanation:

An electrical synapse provides channel of proteins referred to as gap though which two neurons are connected. This connection allows the electrical signal to travel from cell to the other. Electrical synapses are commonly found in the brain and nervous system of an organism

In this synapse, there is a passive flow of ions from one neuron to the other through the gap junction pores. The neuron from which the current flows is called as presynaptic element and is also referred to as upstream neuron while the neuron which receives the current is called as postsynaptic or downstream neuron.  

fertilization, pictured in figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. the egg and sperm each contain one set of chromosomes. to ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. in mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. when a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. in placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in figure 24.23b. the fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. the nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.

explanation: