The appearance of banded iron layers in the rock record between 1.08 and 3.8 billion years ago reflect the alteration of oxygen-rich and oxygen-poor conditions in the ocean at that time is True.
<u>Explanation:</u>
Banded rocks have layers of iron oxide and cherts that contain silica. The layer containing iron oxide has a dark color and the chert layer is red in color. Haematite and magnetite are usually the iron oxides that make up the banded rocks.
Banded rocks were formed by the reaction of iron in the oceans with the oxygen produces by photosynthetic bacteria in the ocean. The reaction caused the formation of iron oxides and their precipitation as Banded iron formations.
The presence of free oxygen is crucial for the formation of banded rocks and the formation reduced drastically after 1800 mya period when atmospheric oxygen availability was reduced. Banded rocks represent the oxygen rich and oxygen-poor condition of the ocean at that time.
Answer:
One sister chromatid is inherited from each parent.
Explanation:
B)<span>When you listen to the heart sounds, you are hearing the flow of blood which stops abruptly when a heart valve closes. This produces the "lub-dub" sounds. 1st heart sound (when the Mitral Valve closes) as the ventricle contracts (systole) and then 2nd heart sound (when the Aortic Valve closes) and the ventricle starts to fill again (diastole)
</span><span>The pulse is the wave of pressure you can feel through the artery walls. This denotes systole.
</span><span>The ECG's QRS complex is the electrical signal that tells the Ventricles to contract. You can see that the QRS occurs right at the beginning of systole and triggers Isovolumetric contraction.
</span><span>So the QRS on the ECG, the pulse wave you can feel (ie. the rise in aortic pressure) and the 1st heart sound all signify SYSTOLE.
</span><span>there a delay between systole of the ECG and the resulting pulse felt in the finger (R-Pulse) </span>because it takes a little bit of time for the pressure to transmit through the body, as the finger is not on the heart (if it was there would be no delay)
Synthesis, as a good way to see synthesis would A + B = AB
Answer:
pruney fingers are caused by shrinking blood vessels. When you soak in water, your nervous system sends a message to your blood vessels to shrink. Your body responds by sending blood away from the area, and the loss of blood volume makes your vessels thinner.
