Alleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each personâs unique physical features. Genes are made up of DNA.Each chromosome contains many genes. A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases.lleles are forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each personâs unique physical features. Genes are made up of DNA.
To make a muscle contract, the acetylcholine produced in the presynaptic neuron of the neuromuscular junction must bind to the nicotinic receptors on the postsynaptic side. Each of these receptors consists of 5 subunits that form a pentagonal structure around a central channel.
Acetylcholine is a chemical messenger, a neurotransmitter, released by nerve cells in many parts of the peripheral nervous system. It controls the contraction of all skeletal or voluntary muscles, for instance. It also affects the contraction of smooth and cardiac muscle.cetylcholineâs Effect On Smooth Muscle. Acetylcholine activates a different type of receptor present in smooth muscle: the muscarinic receptor. When this receptor binds acetylcholine, one result is the release of calcium ions from internal stores.