A Catalyst article about the discovery of puerperal fever by Ignaz Semmelweis a doctor in a maternity ward in Vienna general hospital. The article looks at his observations into death rates and shows how scientists use observations and theories to make practical changes that can improve life. In the case of...

Published by the Wellcome Trust, the 'Big Picture' explores issues around biology and medicine.

This resource looks at several aspects of the immune system including:

• The non-specific immune response
• Specific immune response and antigen recognition
• T cells and B cells
• ...

A Catalyst article about giant asteroids. Astronomers say that, one day, a giant rock from space will collide with the Earth and cause mass devastation. This could lead to the extinction of many species, including humans. The article looks at what can be done to prepare for such an impact and what happened when a...

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A Catalyst article about in vitro fertilisation. About one in six couples gets help from specialists because they cannot conceive. One possibility is to use in vitro fertilisation (IVF). ‘In vitro’ means ‘in glass’ and refers to the fact that fertilisation takes place in a laboratory dish or test tube, hence the...

This Catalyst article describes how the human body is affected by low atmospheric pressure at high altitudes. The article looks at the dangers that await the unwary traveller and explains how, if people understand their bodies, they can avoid the worst problems of life at high altitudes.

This article is from...

This Catalyst article explains how in nature, bioamplification causes substances to become more concentrated as they move from eater to eaten along a food chain. This sequence occurs in relation to the concentration of pesticides like DDT along a food chain, and causes problems for those animals, like birds of prey...

Published by the Wellcome Trust, the 'Big Picture' explores issues around biology and medicine. Written at the time of the H1N1 swine flu outbreak, it looks at the nature of influenza, drugs and vaccines that can fight it.

A Catalyst article describing how the VISTA telescope, which is located in Chile, works. It detects infrared radiation - electromagnetic radiation beyond the red end of the spectrum. This has two great benefits:

*The telescope can detect radiation from distant stars which are otherwise hidden behind clouds...

A Catalyst article investigating chromosomes. In particular, the article looks at genes and explains how the chromosomes and genes a human inherits from their parents can cause problems such as sickle-cell anaemia, cystic fibrosis and Huntington’s disease.

This article is from Catalyst: GCSE Science Review...