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As the volume of blood in the ventricles of the heart increases, with all other factors constant, stroke volume increases till a point. Explain why. (5)

Define stroke volume as the volume of blood expelled by the left ventricle into the aorta per contraction of the heart.Idea that as blood volume in the ventricle increases, this stretches the sarcomeres o...

Answered by Azmaeen Z. • Biology tutor

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How can natural selection create two different species from one species?

For speciation to occur, two populations of a species must become reproductively isolated. This can result from either the formation of a geographic barrier between two populations of the species, prevent...

Answered by Sean K. • Biology tutor

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Guard cells open and close stoma in different conditions. When light intensity is high, potassium ions move into guard cells. Describe how this movement of potassium ions causes the stoma to open.

When the potassium ions move into the guard cells they increase the concentration. This causes water to move into the guard cells from more dilute areas by osmosis. The additional water leads to the guard...

Answered by Emily W. • Biology tutor

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The genetic code is described as degenerate, universal and overlapping. Explain these terms.

The genetic code is universal because all species use the same four bases A,T,C and G, and each base sequence codes for the same amino acid in all species. despite the 64 possible codons (sequence of thre...

Answered by Emily W. • Biology tutor

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Explain the sliding filament theory of muscle contraction

Muscle contraction begins after an action potential reaches the required muscle and causes the calcium ion protein channels on the sarcoplasmic reticulum to open. This allows the calcium ions to diffuse d...

Answered by Isabel L. • Biology tutor

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