4. Ion channels are at the heart of neuron physiology. Using the parameters of location, trigger for opening the channel, and ion selectivity, compare and contrast ligand-gated channels from
voltage-gated channels.
5. Saltatory conduction is a phrase used to describe how an action potential travels down a neuron,
“jumping" from one node of Ranvier to the next. How does the absolute refractory period of
voltage-gated channels facilitate this action potential movement down an axon towards the axon
terminal and not back to the axon hillock?
6. Hyperpolarization is a normal phase of the action potential, but is also a mechanism by which a
neuron can be inhibited from signaling. Describe the ion movement that normally causes the
hyperpolarization at the end of an action potential. In a resting ion (not firing an action
potential), describe one ion movement that would hyperpolarize a neuron. Mentioning threshold,
why would this serve to inhibit that neuron from firing an action potential?

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:

c

explanation:

it's the cell cycle, but cytokines is when the cell divides.

theres 3 stages interphase,mitosis,and cytokines.

interphase prepares the cell for division.

mitosis is the process of dividing the cell,it has 4 parts interphase,anaphase,metaphase,and telophase.

lastly there's cytokines,that's when the cell divides into 2 daughter cells

i was thinking 4.0 v hope this