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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7 Managing the BSE/vCJD episode: an overview

Having concentrated so far on the â€˜scienceâ€™ behind BSE and vCJD, we now turn our attention to how the episode was managed by scientists, politicians and other relevant decision makers. Not surprisingly, we shall find that the themes of communication, risk and ethical issues are inextricably linked to that of decision making (at local, national and international levels).

Over the years, the UK Government implemented a great many Orders and Regulations, amending several of these more
Author(s): The Open University

4 Milk production (lactation)

In this section, you are presented with a fairly complex diagram, Figure 1. The first thing to do when you come to any diagram is to read the cap
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2 How should we think of monotremes?

This section contains the first of the activities, Activity 1. If possible, you should do each activity as you come to it; the text that follows
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1.3.5 A note on graph drawing

There will be many occasions throughout your study of physics when you will need to draw graphs. This subsection gives some important guidelines for this activity.

1. Decide which is the independent variable and which the dependent variable. Plot the independent variable along the horizontal axis and the dependent variable along the vertical axis. This is purely a convention but is why, for instance, we usually plot the time
Author(s): The Open University

1.3.3 Position–time graphs

Tables do not give a very striking impression of how one thing varies with respect to another. A visual form of presentation, such as a graph, is usually much more effective. This is evident from Figure 7, which shows the graph obtained by plotting the data in Table 2 and then drawing a smooth curve through the resulting points.

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1.3.2 Describing positions along a line

To take a definite case, consider a car moving along a straight horizontal road. The car can be modelled as a particle by supposing the particle to be located at, say, the midpoint of the car. It is clearly convenient to measure the progress of the car with respect to the road, and for this purpose you might use the set of uniformly spaced red-topped posts along the right-hand side of the road (see Figure 5). The posts provide a way of assigning a unique position coordinate to the car
Author(s): The Open University

Learning outcomes

After studying this unit you should be able to:

• explain the meaning of all the newly defined (emboldened) terms introduced in this unit;

• draw, analyse and interpret positionâ€“time, displacementâ€“time, velocityâ€“time and accelerationâ€“time graphs. Where appropriate, you should also be able to relate those graphs one to another and to the functions or equations that describe them, particularly in the case of straight-line graphs;

• find the derivati
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Acknowledgements

Video Materials

This extract is taken from S809 Â© 2005 The Open University.

All written material contained within this unit originated at the Open University.

Author(s): The Open University

The injection may be given immediately before the imaging process, or there may, for certain procedures, be a delay of several hours.

The patient's details and the dose being administered are carefully checked by two people before the injection is given. A lead-screened syringe is used to protect the staff from unnecessary radiation dose (see
Author(s): The Open University

6.1 Introduction

Radionuclide imaging is a very valuable way of examining the function of an organ, as opposed to the more structural images obtained by other methods such as X-ray and CT.

The basic principles of radionuclide imaging are as follows:

• a radioactive substance, usually combined with a biologically active compound, is injected into the patient;

• this targets a particular organ or tissue type;

Author(s): The Open University

2.2.2 Collimator

The dimensions of the emerging X-ray beam can be altered by the collimator. This helps to ensure that only the region of interest is exposed to the X-rays.

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4.3 Hierarchies within groups

Within multimale-multifemale groups of the type portrayed in Figure 7f, complex social relationships exist. These animals are â€˜forced togetherâ€™ to defend resources and to avoid predation, but competition for food and mates is substantially greater in large groups. This internal competition has led to males or female
Author(s): The Open University

4.2 Social dynamics

Yet another type of diagram is given in this section. Take a preliminary look at Figure 7, which is a way of illustrating the relationship
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4.1 Group size and collaboration

This section requires you to interpret the data presented in Figures 5 and 6. Figure 5 consists of two bar charts showing (a) the mean day
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References

Durant, J., Bauer, M., Gaskell, G., Midden, C., Liakopoulos, M. and Scholten, L. (2000) â€˜Two cultures of public understanding of science andtechnology in Europeâ€™ in Dierkes, M. and Von Grote, C. (eds) Between Understanding and Trust: the Public, Science and Technology, Amsterdam: Harwood Academic Publishers.
Eurobarometer
Author(s): The Open University

LoM describes this tree dweller as a relative of the raccoon. It belongs to the order Carnivora and is one member of a family generally referred to as procyonids [p. 170], or more commonly the raccoon family. You'll be aware that some members of this family â€“ for example, coatis [p. 174] â€“ are omnivores. As you'll see in the video sequence below, coatis are more typically found in the undergrowth and leaf litter, rather than high up in the trees. (If you need to remind yourself of the lif
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This unit will introduce you to the wide-ranging types of mammals that live in the trees. You will learn how they thrive in this demanding environment, with the help of a range of intriguing adaptations related to their unusual life-styles.

This is the eighth in a series of units about studying mammals. To get the most from these units, you will need access to a copy of The Life of Mammals (2002) by David Attenborough, BBC Books (ISBN 0563534230), and The Life of Mammals (
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Large brain size is a defining feature of Homo sapiens, which means that evolution of increased brain size in Homo is crucial evidence. Indeed, an increase in both the size and the complexity of the brain is a defining feature of primate evolution as a whole. It's possible to estimate brain sizes from fossil skulls or parts of skulls, e.g. by filling what there is of the skull with sand and then measuring the volume of the sand. Use of computer technology fills in â€˜gapsâ€™ in
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As you work through this unit you will come across boxes, like this one, which give you advice about the study skills that you will be developing as you progress through the unit. To avoid breaking up the flow of the text, they will usually appear at the start or end of the sections.

As well as the un
Author(s): The Open University