<span>The mantle is more dense, so it can not B.
Not even A , because the crust sure does contain naturally occurring radioactive material. Heat is also not efficiently transferred to the surface--most ground is cool,
so correct option is none is above that is D
hope it helps</span>
Answer:
Answer is Sinoatrial node, SA.
Explanation:
The sinoatrial node, SA, is known to be a group of cells which are found at the top of the heart.
The electrical signal that is initiated by the sinoatrial node bring about or stimulates the atria and then the ventricle of the heart.
It should be noted that, the sinoatrial node are regarded as the pacemaker cells.
Proteins that affect the structure of dna bound to histones without altering histone chemical structure are called Non-histone protein.
The proteins that remain after the histones have been taken out are known as non-histone proteins. A large group of heterogeneous proteins referred to as non-histone proteins organise and compress the chromosome into higher order structures.
They play a crucial role in regulating processes such nuclear transport, steroid hormone activity, nucleosome remodelling, DNA replication, RNA synthesis and processing, and the transition between interphase and mitosis.
Scaffold proteins, DNA polymerase, Heterochromatin Protein 1, and Polycomb are examples of typical non-histone proteins. This classification area also includes a large number of other structural, regulatory, and motor proteins. Non-histone proteins can be acidic. Other than histones, many proteins have the ability to bind to DNA and change the shape of the chromatin by means of epigenetic processes.
To learn more about non-histone protein-
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Complete question:
The endplate potential (EPP) at the frog neuromuscular junction occurs because ACh simultaneously increases the conductance of the postsynaptic membrane to Na and K
Answer:
TRUE
Explanation:
The Acetylcholine neurotransmitter is released from the presynaptic cell by the process of exocytosis.
Once the molecule is in the intercellular space, it moves forward the postsynaptic membrane to join its receptor in the motor plate.
Once the joining has occurred, the receptor acquires a channel shape allowing the ion transference that will make possible the modification of the action potential. Ions traffic will consist of the pass of sodium and calcium to the interior of the cell and potassium to the exterior. Quantitatively, the interchange Na-K is the most significant.
K+ follows a concentration gradient, while Na+ follows an electrochemical gradient. The interchange results in an increase of positive charges in the interior of the muscular cell.
Whenever there is a sufficient number of Acetylcholine receptors are active, the depolarization threshold of the motor endplate is exceeded. This activates an action potential that extends to the rest of the muscle membrane.
Nucleic acids. They contain a phosphate base and a nitrogen group.
