7.2 Types of active galaxy

The field of active galaxies is recognised as one of increasing importance. But how do we know there are different kinds of galaxy? What are active galaxies? How are they powered? This unit examines the different types of active galaxy and looks at the crucial role of the active galactic nucleus and the energy source at its heart.

8.1 Introduction

From the mouse-deer to the elephant, plant eaters come in all shapes and sizes. But how do they manage to flourish on a salad diet? In this unit we will examine the special features that allow them to extract their nutrients from leaves, and see how some plants protect themselves from these predators. This is the fourth unit in the â€˜Studying mammalsâ€™ series.

7 Plant defences

From the mouse-deer to the elephant, plant eaters come in all shapes and sizes. But how do they manage to flourish on a salad diet? In this unit we will examine the special features that allow them to extract their nutrients from leaves, and see how some plants protect themselves from these predators. This is the fourth unit in the â€˜Studying mammalsâ€™ series.

4.2 Digesting cellulose

From the mouse-deer to the elephant, plant eaters come in all shapes and sizes. But how do they manage to flourish on a salad diet? In this unit we will examine the special features that allow them to extract their nutrients from leaves, and see how some plants protect themselves from these predators. This is the fourth unit in the â€˜Studying mammalsâ€™ series.

7 Unit summary

James Clerk Maxwell (1831-1879) is arguably the father of electromagnetism, and unarguably one of the greatest physicists ever. Einstein called Maxwell's equations 'the most important event in physics since Newton's time, not only because of their wealth of content, but also because they form a pattern for a new type of law'. This unit will examine Maxwell's greatest triumph, the prediction that electromagnetic waves can propagate vast distances through empty space and the realisation that light

5.1.6 Pulling it all together

James Clerk Maxwell (1831-1879) is arguably the father of electromagnetism, and unarguably one of the greatest physicists ever. Einstein called Maxwell's equations 'the most important event in physics since Newton's time, not only because of their wealth of content, but also because they form a pattern for a new type of law'. This unit will examine Maxwell's greatest triumph, the prediction that electromagnetic waves can propagate vast distances through empty space and the realisation that light

Next steps

Water is a natural resource that is vital for human survival and health, although only a tiny fraction of the Earth's supply is available to humans and terrestrial animals. In this unit we look at threats, such as pollution, to water's capacity to support life around the world.

2.4.1 Remarks

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.4 Homeomorphic surfaces

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.8 Sphere

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.7 Two-fold torus

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.6 Torus with 1 hole

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.5 Projective plane

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.4 Klein bottle

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.3 Torus

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.2 Möbius band

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3.1 Cylinder

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.3 Paper-and-glue constructions

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.2.4 Boundary numbers

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.

2.2.3 Surfaces with boundary

Surfaces are a special class of topological spaces that crop up in many places in the world of mathematics. In this unit, you will learn to classify surfaces and will be introduced to such concepts as homeomorphism, orientability, the Euler characteristic and the Classification Theorum.