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How does the kidney filter out different molecules?

In the blood flowing through the kidneys, you find lots of different substances, like glucose and amino acids (which the body wants to keep and use) and urea (which the body wants to get rid of). The first i...
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Answered by Isobel E. Biology tutor
4587 Views

((2x + 3)/(x-4)) - ((2x-8)/(2x+1)) = 1

x=0.81
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Answered by Amelia S. Maths tutor
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A 10kg cube of iron with length 5cm is resting on a table surface. Assuming the acceleration under gravity of the block is 9.81ms^(-2), what is the pressure on the table?

Pressure is given by P=F/A, where F is force and A is area. Neither are given in the question, but A is the area of the cube in contact with the table; this is the area of one face of the cube, so A=L L=0.05...
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Answered by William H. Physics tutor
4303 Views

You are shown a diagram of a right angled triangle, with the hypotenuse labelled c and the other sides labelled a and b. If a is 7m long and c is 10m long, what is the length of b?

A simple implementation of Pythagoras' Theorem a 2 +b 2 =h 2 , and as in the question c is the hypotenuse, a 2 +b 2 =c 2 . (Side Note - in exams, the question may not specify which length is the hypotenuse -...
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Answered by William H. Maths tutor
4469 Views

Explain how DNA replicates inside a cell

DNA is made up of 4 bases (Adenine, Thymine, Guanine, Cytosine) Adenine, guanine = purine 'Pure AGony' Thymine and cytosine = pyramidines Adenine pairs with thymine (2 Hydrogen bonds - '2 people know where i...
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Answered by Claire D. Biology tutor
3910 Views