6 Permeability

It is important to distinguish clearly between porosity and permeability. Porosity is a measure of how much water can be stored in a rock, whereas permeability is a measure of the properties of a rock which determine how easily water and other fluids can flow through it (see Section 4). Permeability depends on the exte
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1.3.3 A breeding experiment: stage two

We now turn to the second stage of the breeding experiment, but this time we will follow the phenotypes and genotypes simultaneously. The purple (Gg) grains of the F1 generation are planted and when these have developed into mature F1 plants they produce male and female flowers. These F1 plants are crossed with each other, as shown in Figure 8. The fertilised ovules develop into grains borne on cobs, and these grains are the beginning of the second f
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4.3.1 Stage 1: Continental rifting (northern Red Sea stage)

There are two mechanisms for breaking up a continental plate, the simplest of which is to pull it apart under lithospheric extension, forcing the mantle to rise up to occupy the ‘space’ that otherwise would be left by the thinned overlying plate (Figure 6a). Continued extension of this already thinned plate wi
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3.9 Moon41: Apollo 15 station 2

The panorama was collected by James B. Irwin at Station 2. David Scott is to the left of the rover. He is examining a boulder. The large hill to the left of the rover is the summit of Mt. Hadley Delta. (QuickTime, 400KB, note: this may take some time to download depending on your connection speed)

2.2.2 Energy and conservation

Newtonian mechanics is concerned with explaining motion, yet it contains within it the much simpler idea that some things never change. Take the concept of mass, for example, which appears throughout Newtonian mechanics, including the law of gravitation. In Newtonian mechanics, mass is conserved. This means that the mass of the Universe is constant and the mass of any specified collection of particles is constant, no matter how much rearrangement occurs within the system. A chemist might take
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Acknowledgements

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1.3 Chromosome structure and DNA replication

DNA replication is closely linked to chromosome replication, which in turn is linked to cell division, which includes the nuclear division of mitosis. This raises an intriguing question: how many DNA molecules are present in a chromosome?

Chromosomes are composed of DNA intimately associated with proteins. When the chromosomes become visible at the beginning of mitosis, the DNA has already been replicated, and the chromosomes are double structures; that is, each chromosome consists of t
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1 1.2 How DNA is replicated

Cell division involving the nuclear division of mitosis produces two progeny cells, which contain identical genetic material, which is also identical with that of the original parent cell. This is how a fertilized egg grows into an adult many-celled organism. For one cell to become two new ones with identical genetic material, the DNA in each chromosome must undergo a process in which an identical copy is made.

As noted above, Watson and Crick postulated that DNA base-pairing provides a
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Figures

Figure 1 Science Photo Library;

Figure 8a This photograph has been provided by Railway Technical Research Institute in Japan;

Figure 22 Proceedings of the Royal Society A248 464. The Royal Society;

F
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1.10 Changing sea-level

Sedimentary rocks reveal how environmental conditions in Britain's geological past were extremely different from those of the present day (in fact ‘Britain’, like the rest of the Earth's geography is transitory when viewed in terms of the very long span of geological time). As well as evidence from sedimentary rocks, recent landforms also indicate that in the more recent geological past (within the Quaternary Period), sea-level was not the same as it is at present.

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5.3.2 Conclusion after reading this article:

The paper suggests that the factors that had long been considered responsible for neurodegenerative disease are also important for normal neuronal function. For example, they exert a physiological homeostatic effect by reducing excitatory transmission in Author(s): The Open University

Europe and the law
This unit will give you a basic understanding of EU law and the interaction between EU and domestic law. It will provide a brief explanation of the European Convention on Human Rights and other European legislation, as well as the background to such institutions as the European Council, the European Commission, the European Parliament and the European Court of Justice. First publish
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Ficure 2: Crown copyright
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1.4: Price ratios and price indices

Aims The main aim of this section is to look at some different ways of measuring price increases.

In this section you will be looking at measuring price changes using price indices. In order to do this you will need to understand the concept of a price ratio. Price ratios are another way of looking at price increases or decreases, related to the proportional and percentage increases and decreases you have seen before.


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4 Subtracting on paper

If the numbers you want to subtract are too large for you to do the calculation in your head, you can use a calculator. Alternatively, you can do the calculation on paper.

Write your starting number at the top with the number you want to subtract from it underneath. Because the order in which you subtract one number from another matters, it is important to put the correct numbers on top and bottom. Then draw a line underneath.

Write the numbers so the digits form columns and they
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Introduction

This course focuses on the problem of greenhouse gas emissions, especially carbon dioxide, and explore what you can do to lighten those emissions to help reduce the rate of climate change. You will assess your ‘carbon footprint’ and see what actions you and, if relevant, other household members could take to lighten that footprint. You will also better understand which actions are more and less effective, and the scope and limits of what individuals can do at the personal and household le
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Copyright © 2016 The Open University

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