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3.8 Glucagon

Glucagon is another hormone produced by the pancreas.

Question: Can you recall which cells make glucagon?

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14 Unit questions and answers

Note: Question 1 is included in Section 3.

Question 2


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8 Managing the BSE/vCJD episode up to May 1990

BSE was formally recognised as a new disease in November 1986. However, this information was kept under ‘embargo’ at first while an initial epidemiological study – involving the collection of data from 200 herds – was started. The Ministry of Agriculture, Fisheries and Food (MAFF) was officially informed about BSE by the Chief Veterinary Officer (CVO) in June 1987. By December 1987, those responsible for analysing the data from the initial epidemiological study had concluded that the
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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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5.3 Heat production

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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Introduction

Mammals come in a bewildering variety of shapes and sizes and yet all of the 4700 or so species have some characteristics in common. Indeed, it's the existence of these common features that justifies the inclusion of all such diverse types within the single taxonomic group (or class) called the Mammalia.

This is the first 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 Attenboroug
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1.7.2 End-of-unit questions

Question 25

Table 8 shows the atmospheric pressure P in pascals (Pa) at various heights h above the Earth's surface. Plot a graph to give a visual representation of the data in the table. Be careful to label your axes co
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1.4.6 The signed area under a constant velocity–time graph

There is a simple feature of uniform velocity–time graphs that will be particularly useful to know about when we come to consider non-uniform motion in the next section. It concerns the relationship between the velocity–time graph and the change in position over a given time interval. Consider the following problem. A vehicle travels at a velocity vx = 12 m s−1 for 4 s. By how much does its position change over that interval?

The answer, fro
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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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7 Conclusion

Activity 15

Perhaps you are asking yourself why there are so many different imaging modalities. Is there not one that will do everything that is required? The answer, at the moment, is ‘No’. With most of the imaging techniques, we cons
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2.2.4 Film cassette and grid

As the X-rays pass through the patient some of them will be scattered and will therefore not follow the expected line through the patient. If these reach the detector they will blur the image. Some of the scattered radiation can be removed by a grid, usually oscillating, placed between the patient and the detector.

Analogue imaging systems use either film alone (rarely) or a combination of a film and fluorescent material (phosphor). The phosphor fluoresces and produces visible light whi
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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 Unit summary

  • Many of the large icy bodies in the outer Solar System are internally differentiated. Thanks largely to tidal heating, some, especially Europa, are likely to have an ocean sandwiched between the icy exterior and the rocky core. Others may have had such an ocean in the past.

  • Wherever water rests on warm rock, water must percolate into it and become heated. This will cause hydrothermal convection to begin. Hot, chemical-rich water will emerge
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2.5 Heat and life

The weight of evidence in the case of Europa points strongly towards ice overlying salty water, at least within the past few millions years although not necessarily today. There are signs that localised heating episodes have melted and fractured the ice. The intensity of tidal heating has probably waxed and waned in step with fluctuations in the amount of forced eccentricity of Europa's orbit, but we can anticipate that conditions on Europa would have varied through a broadly similar range du
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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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Acknowledgements

The content acknowledged below is Proprietary (see terms and conditions) and is used under licence. This content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence

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

T
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6 Reflections

DA opens the TV programme by stating that ‘monkeys and apes have the richest social life of all mammals’. I have explored the importance of colour vision in the interactions between individuals and discussed how gestural and vocal communication add considerably to this richness. But ultimately, it is their ability to be innovative, to discover new ways of obtaining foods, to learn from one another (so-called cultural learning), to form friendships, alliances and coalitions between individ
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3.5.2 Vocal communication

In order to be able to state that animals are communicating vocally with one another, scientists need to demonstrate that particular sounds made by one individual can be understood and acted upon by others.

Activity 5

You will be
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