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6 Thermoregulation and mammalian fur

A coat of profuse mammalian body hair is commonly called fur. Fur provides insulation, which is a property that one first thinks of as useful for mammals to help retain body heat. Fur is a unique and fundamental feature of mammals, though not all living species possess it.

Question 12

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3 Reproduction in marsupials

The study of mammals requires you to deal with measurements, which we call numerical ‘data’, and you will get practice with compiling and analysing data if you work through all the units in this series. We assume only that you can add, subtract, multiply and divide. In this section, we ask you to use units
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1.5.2 Instantaneous acceleration

The procedure of Question 15 for determining the instantaneous velocity of the car can be carried out for a whole set of different times and the resulting values of vx can be plotted against t to form a graph. This has been done in Figure 28, which shows how the velocity varies with time. At time t = 0 s, the car has zero velocity because it starts from rest. At later times, the velocity is positive because the car moves in the direction of in
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1.4.5 Velocity–time and speed–time graphs

Just as we may plot the position–time graph or the displacement–time graph of a particular motion, so we may plot a velocity–time graph for that motion. By convention, velocity is plotted on the vertical axis (since velocity is the dependent variable) and time (the independent variable) is plotted on the horizontal axis. In the special case of uniform motion, the velocity–time graph takes a particularly simple form – it is just a horizontal line, i.e. the gradient is zero. Ex
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1.1 The description of motion

The concepts that have been developed to allow the description of motion – concepts such as speed, velocity and acceleration – are now so much a part of everyday language that we rarely think about them. Just consider the number of times each day you have to describe some aspect of motion or understand an instruction about motion; obey a speed limit or work out a journey time. We may take the description of motion for granted, but the concepts involved are so fundamen
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Acknowledgements

Video Materials

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

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


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6.3.1 Collimator

Without a collimator, gamma rays from all directions would be collected by the crystal and no useful image could be obtained. Gamma rays cannot be focused by a lens but a collimator consisting of a series of holes in a lead plate can be used to select the direction of the rays falling on the crystal. Most collimators in use today are parallel hole collimators. A parallel hole collimator is shown schematically in Author(s): The Open University

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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2.4 How thick is Europa's ice?

You learned in Section 1.4 that geophysical data show the ‘icy’ outer part of Europa to be about 100 km thick, but that the information is inadequate to distinguish between the extreme possibilities of solid ice all the way down to the bedrock and a floating sheet of ice supported above a liquid ocean (Author(s): The Open University

2.3.2 The crater Pwyll

You might also have noted that there are no obvious impact craters visible in Figure 16 (see Section 2.3.1). In fact there are a few. One is a bright spot, 15 km in diameter, surrounded by a dark halo of ejecta that occurs 10 mm from the top edge and 65 mm from the left-hand edge of the figure. Another is a s
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Learning outcomes

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

  • discuss processes upon and within, and internal structure of, differentiated icy bodies (primarily large satellites) in comparison with the terrestrial planets;

  • describe the conditions that may be required to originate and foster life in an icy body and discuss the likelihood of their having occurred;

  • recognise the moral and ethical issues of landing spacecraft on potential life-bearing worlds and appre
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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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3.3 Seeing red

Activity 3

Watch the TV programme from 20.37–24.06 and reread LoM pp. 247–248 and 255. Write a paragraph of about 120 words explaining why the inability to detect the colour red would disadvantage anthropoid primates. Try also to in
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3.2 Colour vision

DA stresses that colour vision is very important in primates, not only because colour is used ‘in sexual displays’ such as advertising a female's receptiveness to mating [p. 275], but also to identify ripe fruit [p.247] and to select nutritious leaves [p. 255]. This section discusses these points in more detail and explains how the visual system in primates is able to detect colour.

White light is composed of light of different wavelengths, from 300–800 nanometres (nm); 1 nm is on
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References

Durant, J., Bauer, M., Gaskell, G., Midden, C., Liakopoulos, M. and Scholten, L. (2000) ‘Two cultures of public understanding of science andtechnology in Europe’ in Dierkes, M. and Von Grote, C. (eds) Between Understanding and Trust: the Public, Science and Technology, Amsterdam: Harwood Academic Publishers.
Eurobarometer
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2.3 ‘Go Say’ science promotion events

An increasing number of science museums and science centres hold regular organised events that stand apart from their exhibitions. The Dana Centre, which now has a permanent venue in the Wellcome Wolfson Building at the Science Museum, holds 10–20 events each month. They are designed to provoke discussion through a blend of debate, art, multimedia and performance, covering issues such as the ethics of prolonging the life of foetuses, the role of science in alleviating poverty, and what is,
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2.2 ‘Go See’ science promotion events

Every year, the BA (British Association for the Advancement of Science) runs a week-long Festival of Science in a different town or city, claiming it to be the largest public celebration of science in the country. The events are diverse in topic and character. The 2004 Festival in Exeter, for example, included a Presidential lecture on the responsibility of scientists, an exhibition on climate change, and an excursion to a nearby car park to test geometry by chalking lines on the ground. Fest
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2.1 Institutional science promotion events

Nowadays, engaging with science through an institutional science promotion event can be quite straightforward. You can find out about such events by, for example, reading posters in your local library, watching a science documentary on TV or browsing the internet. The range of such outreach events is remarkable – from long-standing mainstream programmes such as the Royal Society Christmas lectures on TV and the annual BA (British Association for the Advancement of Science) Science Week, to
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Introduction

For many years, the view that dominated the science–public realm was that if only ‘the public’ were educated more, they would better appreciate the intrinsic value of science in their lives. Moreover, under this approach, people were too often seen as ‘empty vessels’ waiting to be filled with scientific knowledge that was transmitted one-way from experts to citizens – an idea that you will recognise as the ‘deficit model’ of how ‘the public’ understands science. With a few
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5 Summary

Domesticated organisms evolve in artificial environments under artificial selection, and opportunistic or enforced hybridisation often occurs between species that would not normally interbreed. Natural selection cannot be eliminated and continues to operate. At least two different forms of dwarfism are common in domesticated livestock and humans, but only the rarer midget type of dwarfism occurs in wild lineages. Domesticated mammals and birds have distinctive patterns of skin pigmentation th
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