Answer:
(B) It is better for the cell if most molecules are prevented from entering.
I hope this helped at all.
Explanation:
In neurology, postganglionic nerve fibers are autonomic nerve fibers from the ganglion to the effector organ. These, unlike preganglionic fibers (whose sole neurotransmitter is acetylcholine) have a variety of neurotransmitters to fulfill their functions.
Neurotransmitters
The neurotransmitters of postganglionic fibers are varied, and are distributed as follows:
In the parasympathetic nervous system, neurons are cholinergic (Acetylcholine is the primary neurotransmitter)
In the sympathetic nervous system, neurons are mostly adrenergic (norepinephrine-epinephrine and / or norepinephrine, both have the same chemical structure, but epinephrine has a methyl group unlike norepinephrine that has a hydrogen, instead of a methyl group - act as the primary neurotransmitter) Two exceptions to this are the sympathetic innervation of the sweat glands and the piloerector muscles where the neurotransmitter in both pre and post ganglionic synapses is acetylcholine and in the vessels of the renal cortex where dopamine is used as the main neurotransmitter. Another exception is the sympathetic innervation of the medulla of the adrenal gland, which is innervated by preganglionic fibers, and subsequently uses acetylcholine as a neurotransmitter. Adrenal medulla cells are, in fact, modified postganglionic neurons that secrete epinephrine and norepinephrine directly into the bloodstream rather than a synapse.
In both divisions of the autonomic nervous system, postganglionic neurons express nicotinic acetylcholine receptors to receive signals from preganglionic neurons.
1. Passage of a sperm through the corona radiata of the oocyte.
2. Penetration of the zona pellucida.
3.Fusion of the plasma cell membranes of the oocyte and sperm. after fusion the sperm head and tail enters the oocyte but plasma membrane of sperm doesn't.
4. Completion of the second meiotic division of the oocyte. this creates female pronucleus and polar body 2.
5. Formation of the male pronucleus (nucleus of sperm enlarges)
6. Breakdown of the pronuclear membranes and restoration of diploid number of chromosomes.
Answer:
Hydrolysis.
Explanation:
Hydrolysis is a type of chemical reaction in which a molecule of water breaks down into one or more chemical bonds.
The term is used broadly for these reactions: substitution, elimination, and fragmentation reactions in which water is the nucleophile.
Biological hydrolysis is the division of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into small parts. When a carbohydrate is broken down into its component sugar molecules by hydrolysis process, that is called saccharification.
After breaking down by hydrolysis process, carbohydrates produce small particles or molecules. As an example, by the hydrolysis process, sucrose produces glucose and fructose.
V= IR ==> I = V/R
For A: I = 9/3 = 3 amps
for B: I = 3/(1/2) = 6 amps
