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BIO113 Studying Mammals Unit 4: Plant Predators - OPEN University
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Open University
S182_4 10 Hours
Introductory
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Course Description
The plant predators, or herbivores, are a varied
group, but they share certain characteristics. Many of them are large;
among the smallest is the chevrotain (or mouse-deer) at about two
kilograms weight, and the elephant is the largest, with a typical bull
male weighing around six tonnes. In this unit we'll be looking in more
detail at some of the problems and consequences of adopting a
plant-eating way of life. Leaves are a much less nutritious food than
most kinds of animal material, so large herbivores have to eat large
quantities of plants and they have special ways to digest their food. We
will look at how leaves work and the ways in which herbivores are
adapted to survive on their plant-based diets.
This is the fourth 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 (2002) on DVD, which
contains the associated series of ten BBC TV programmes. OpenLearn unit S182_8 Studying mammals: life in the trees
contains samples from the DVD set. You should begin each unit by
watching the relevant TV programme on the DVD and reading the
corresponding chapter in The Life of Mammals. You will be asked
to rewatch specific sequences from the programme as you work through the
unit.
By the end of this unit you
should be able to:
- describe the particular
problems in digesting plant material;
- give
examples of the ways in which teeth are modified for a herbivorous
diet;
- explain the importance of
digestive enzymes;
- explain the
importance of microbes in digesting plant material;
- compare the main features of the digestive systems of
ruminants and hindgut fermenters;
- describe
some of the ways in which plants can defend themselves against
herbivores;
- explain some of the
tactics that scientists use to investigate problems by developing and
testing hypotheses.
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Introduction
 Introduction
Resource- The plant predators, or
herbivores, are a varied group, but they share certain characteristics.
Many of them are large; among the smallest is the chevrotain (or
mouse-deer) at about two kilograms weight,...
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1 The herbivores
- 1 The herbivores Resource
- 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...
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2 The herbivore lifestyle – living on leaves
- 2 The herbivore lifestyle – living
on leaves Resource
- Leaves are a much less nutritious
food than most kinds of animal material, so large herbivores have to eat
large quantities of plants and they have special ways to digest their
food. As author David Attenborough...
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3 Herbivore teeth
- 3 Herbivore teeth Resource
- Tables are a useful way of
recording key information. The headings for Tables 1 and 2 have been
prepared for you, and you can copy and complete the tables in your
notebook. If you need to find any of this...
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4 Digesting plant material
- 4.1 A brief digression about
digestion Resource
- There are many new scientific
terms introduced in this unit. Are you making your own lists of them? If
you were to encounter these terms in a fresh context (perhaps on a
website, or during your own reading...
- 4.2 Digesting cellulose Resource
- Figure 3 in this section contains a
lot of information and many terms that are probably new to you. Set
aside the detail for the moment, read the caption and try to get an
overall impression. You should...
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5 Digestive processes
- 5.1 Ruminants Resource
- The earliest ruminant was probably
an ancestor of the present-day chevrotain. The chevrotain skeleton
appears to have remained virtually unchanged for the past 30 million
years and, although there are...
- 5.2 Pseudo-ruminants Resource
- Animals in the third suborder of
the Artiodactlya, the pigs, peccaries and (according to most
authorities) the hippopotamuses (suborder Suina), use a slight variant
on the ruminant method, and are often...
- 5.3 Hindgut fermenters Resource
- 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...
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6 Grazers and browsers
- 6 Grazers and browsers Resource
- A good deal of the discussion so
far has been related to animals that eat leaves in the form of grass and
other herbaceous plants, the grazers, but this is not the only type of
plant food. Also available...
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7 Plant defences
- 7 Plant defences Resource
- Watch the ‘Plant Predators’
programme from 05.03–12.07 and make notes in answer to the following
questions.
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8 Shortage of nutrients
- 8.1 Introduction Resource
- You know by now that plants can
synthesise all the complex molecules that make up their tissues and
seeds from very simple molecules – water, carbon dioxide and minerals
from the soil. Mammals, on the...
- 8.2 Protein shortage Resource
- Most plant leaves and stems
contain very low levels of protein and so herbivores need to make
maximum use of the amount available. You will recall that proteins in
the diet are digested to amino acids,...
- 8.3 Shortage of minerals Resource
- You may be familiar with salt
licks that are provided for domesticated cattle. In the wild, grass is
also often low in minerals (e.g. it has almost no sodium and very little
calcium), so grazers may have...
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9 Wildebeest migration
- 9 Wildebeest migration Resource
- The skill of thinking in a
scientific way is as much a part of being a scientist as is knowing
facts – perhaps more so. In this series of units, you'll not only come
across facts about particular techniques,...
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10 Living in herds
- 10 Living in herds Resource
- Wildebeest are only one of the
species of plant predator that live in herds. Many others do too.
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References and Acknowledgements
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There are currently no items in this folder.
Copyright 2007,
by the Contributing Authors.
Cite/attribute Resource.
administrator. (2010, January 30). BIO113 Studying Mammals Unit 4: Plant Predators - OPEN University. Retrieved September 07, 2010, from Free University Courses OCW Courses OpenCourseWare Freeversity Foundation Web site: http://www.freeversity.org/science-and-mathematics/biology/bio113-studying-mammals-unit-4-plant-predators-open-university.
This work is licensed under a
Creative Commons License
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