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Describe how the human body can prevent the entry of organisms that cause disease. Include physical barriers and chemical defences in your answer.

Physical barriers: skin to prevent entry of organisms into the bloodstream cilia lining the nasal passages / bronchi to prevent entry to lungs / remove mucus scabs to prevent entry of microorganisms into the...
KM
Answered by Khadija M. • Biology tutor
10460 Views

How do I find the expression for the nth term in a series of numbers?

First write down the series of numbers e.g. 8, 12, 16, 20. Calculate the difference between each term in the series 12-8 = 4, 16-12 = 4, 20-16 = 4 This shows that the expression will begin with 4n as the dif...
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Answered by Megan B. • Maths tutor
21859 Views

Why should we use biodiesel rather than regular petroleum diesel?

The combustion of biodiesel produces less carbon dioxide, sulfur dioxide and particulates than that of regular diesel. This causes less global warming from the greenhuse effect and less sulfur dioxide pollut...
BM
Answered by Bradley M. • Chemistry tutor
3243 Views

Factorise and solve x^2 - 8x + 15 = 0.

Whenever faced with a quadratic equation in the form of AX^2 + BX + C = 0, the first thing you do is factorise it, which will look something like this: (X )(X ) = 0.You can see from this that when you multip...
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Answered by Zarmala N. • Maths tutor
3892 Views

Which of the basic life processes is described here? The ability of multicellular organisms to regulate their internal environment so that it stays optimum for cellular survival.

Homeostasis
AM
Answered by Alice M. • Biology tutor
3323 Views