In biology, histones are highly alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes. They are the chief protein components<span> of </span>chromatin<span>, acting as spools around which DNA winds, and playing a role in </span>gene regulation<span>.</span>
Formation of island chains occurs when convergent boundaries interact and is denoted as option A.
<h3>What is Convergent boundary?</h3>
This refers to an area where two or more lithospheric plates collide in the earth.
When the y interact, island chains are formed which consists of sea with sparse islands around the area.
Read more about island chains here brainly.com/question/12433780
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Answer: B. pressure changes in the thorax
Explanation:
The veins are the blood vessels which returns the deoxygenated blood from all the tissues and cells of the body back to the heart. The ventricular systole, venous valves, activity of the skeletal muscles and neural control over venoconstriction all influence the movement of the blood in the venous.
The pressure changes in the thorax occurs due to inspiration and expiration. During the process of inspiration, the diaphragm below the lungs contracts and moves downward while the muscles of the ribs pulls downward. When the size of the thoracic cavity increase the air pressure inside the cavity decreases and vice-versa. The pressure inside the thoracic cavity is not related with the movement of the venous blood as it regulates the exchange of the gases not the blood.
I think it 700 million years because I took the same question and that’s what I put.
