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1 Genetic manipulation of plants and GM crops: an introduction

In this unit we will consider the genetic manipulation of plants, and the production of GM crops. A great deal has been written about the science of GM crops and the controversial issues surrounding their introduction around the world. In the study time available, we will focus on a small number of selected issues.

In this unit you'll have the opportunity to learn more about the science that has been used to engineer a range of GM crops, and examine both the science and social concerns
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Learning outcomes

By the end of this unit you should be able to:

  • understand more about the science that underlies the development of genetically modified organisms and in particular how gene transfer is brought about;

  • know something of the potential benefits and uncertainties associated with gene transfer and the high levels of technical ingenuity involved;

  • be better able to understand the science that underpins the development of Golden Rice and understand why the u
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3.1 How do organisms take up iron?

Nearly all organisms are able to take up iron. However, only a handful of organisms have had their iron-uptake chemistry studied. The organism that has received most attention (other than human) is a single-cell, prokaryotic bacterium (found in the human large intestine and elsewhere), called Escherichia coli (abbreviated to E.coli), a high-resolution image of which is shown in Author(s): The Open University

3.4.3 Summary of Section 6

  1. For the first week after fertilization, the conceptus (early embryo) foats freely in the female reproductive tract, obtaining some of its nutrients from the fuid in which it is bathed.

  2. The fertilized egg begins a series of divisions to give 2, then 4, then 8 undifferentiated cells. There is no net cell growth, so each generation of cells is smaller than the last.

  3. The 8- to 16-cell division is different, and important. Each
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Introduction

We have seen that where precipitation reaches the ground, some runs off the surface into streams and rivers and some of it infiltrates, passing through the soil. Water that reaches the water table to become groundwater may eventually re-emerge at the surface as springs where the water table intersects the surface. Almost all streams and rivers have springs or seepages as their ultimate source, or are fed by them at various points along their courses.

This unit is from our archive and is
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1.3.4 Coil conformations

In addition to the repetitive helical and pleated sheet structures, there are other non-repetitive, and therefore more varied, elements of secondary structure called coil conformations. The lack of regular repetitive order in coil conformations does not, however, mean that these structures are disordered or unstable. In fact, it is clear from X-ray diffraction studies of proteins that these regions are consistent in the conformation that they adopt.

Regions of disorder do exist,
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Acknowledgements

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Grateful acknowledgement is made to the following sources for permission to reproduce material in this unit:

The content acknowl
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1.5.6 Velocity and acceleration as derivatives

Recalling that the instantaneous velocity of a particle at time t is given by the gradient of its position–time graph at that time, we can now use the terminology of functions and derivatives to say that the velocity of the particle is given by the derivative of its position function. In terms of symbols:

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1.5.4 Functions and the function notation

In Figure 25, the position x of the car depends on the time t. The graph associates a particular value of x with each value of t over the plotted range. In other circumstances we might know an equation that associates a value of x with each value of t, as in the case of the equation x = At + B that we discussed in Section 3. You can invent countless other ways in which x depends on t: for instance x = 
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2.6 How can we find out more about Europa?

There are currently no scheduled missions to Jupiter's moons, since NASA's Jupiter Icy Moons Orbiter (JIMO) was cancelled in 2005, but Europa remains a high priority target for both NASA and ESA, so a mission with simlar objectives to JIMO seems likely by about 2020. On arrival at Jupiter, JIMO would have gone into orbit first round Callisto, then Ganymede and finally Europa.

The main objectives of JIMO at Europa would have been to:

  1. Determine the
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3.4 Stereoscopic vision

DA explains that ancestral monkeys had to ‘decide whether a branch was within reach of a stretch or a jump – or beyond either’ [p.248]. Individuals that were able to judge distances between themselves and branches more accurately had a competitive edge over other individuals, which led to the development in primates of stereoscopic vision. Stereoscopic vision evolved convergently in carnivores that judge distances to capture fast-moving prey.

The field of view of a single eye is t
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4.2 Other members of the bear family

Other omnivorous species of bear include the Asian black bear, the North American black bear and the Andean spectacled bear. Although polar bears spend their winters hunting seals out on the Arctic sea-ice, they have to come ashore when the ice melts in spring and find other sources of food.

Activity 2
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5.3 Hindgut fermenters

The odd-toed ungulates (comprising the order Perissodactyla), the horses, tapirs and rhinoceroses, are hindgut fermenters, as are elephants. Update Table 2 with this information. These animals have a relatively simple, small undivided stomach, but this time an even larger caecum and colon where the microbes are housed and whe
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6 Reflection

If you are working through all the units in this series, you'll be aware that this unit has taken a somewhat different tack from earlier ones. I've used rodents to explore some fundamental biological principles that have a relevance far beyond this particular order. It is especially appropriate to talk about issues such as biological success in connection with rodents, given their very wide geographical distribution and the very large number of rodent species and individuals. You'll recall (f
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3.5 Line graphs

To illustrate how to create and use line graphs, we will use the example of a calibration curve.

A calibration curve is a type of line graph in which the response of a measuring device to a series of known concentrations of a substance is plotted. You can then make a measurement of an unknown sample – in the case we're about to examine, blood serum samples from new-born infants – and use the calibration curve to work out what concentration of substance is present.


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Learning outcomes

By the end of this unit you should be able to:

  • read data presented in tables;

  • use scientific notation to express both large and small quantities;

  • appreciate why chemists use different models to represent molecules;

  • identify the number and type(s) of atom present in a molecule from its chemical formula;

  • identify the reactants and products of a reaction in a chemical equation;

  • read and write using chemical
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Introduction

This unit is an introduction to chemistry concepts, using water as the main illustration. Much of the unit is devoted to exploring the smallest water particle – a water molecule – what it is and how it gives rise to the particular properties of water. The unit also explains powers of ten and scientific notation, which are a convenient way of expressing both very large and very small numbers. It is a good introduction to science.

This unit is an adapted extract from the course
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9 Sedimentation at the end of the Caledonian Orgeny; Section 10 Legacy

The document attached below includes the ninth and tenth sections of Mountain building in Scotland, as well as the index. In these sections, you will find the following subsections:

  • 9.1 Introduction

  • 9.2 The Old Red Sandstone and the Devonian Period

  • 9.3 Distribution and stratigraphy of the Late Silurian to Devonian Basins

  • 9.4 Sedimentation and tectonics in the Midland Valley

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8.1 Introduction

We have learned so far that physical energy from the environment is transduced into electrochemical messages that affect the nervous system and give rise to psychological experiences, that is, produce sensations and perceptions. Sensation refers to the initial process of detecting and encoding environmental energy. The first step in sensing the world is performed by receptor cells, which in the case of hearing are the hair cells in the cochlea. Perception on the other hand, generally refers t
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Summary

The ear is made up of the outer, middle and inner ears. The outer ear consists of the pinna, the external auditory canal and the tympanic membrane. The middle ear is air-filled and contains the middle ear ossicles. The inner ear is fluid-filled and contains the cochlea, the semicircular canals and the vestibule.

Sound in the external environment is channelled into the auditory meatus by the pinna and impinges on the tympanic membrane causing it to vibrate. These vibrations are transmitt
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