A Catalyst article about the fruit fly which has played a succession of key roles in developments in biological science over the last 100 years as a laboratory subject in genetics.

Researchers have found that many aspects of the biochemistry of fruit flies and humans are similar. It is due to the fact that...

This Catalyst article looks at harlequin ladybirds, just one of the invasive species that has spread through Western Europe. Over the last century there has been a dramatic increase in the movement of so called alien species around the world as a consequence of international trade and travel. Invasive alien species...

A Catalyst article devoted to food chains. This article looks at photosynthesis and the loss of energy from plants to animals throughout the food chain. How this limits the number of animals that can survive on the energy fixed by a patch of vegetation is explained. Foraging characteristics and how many animals can...

A Catalyst article looking at the evidence for evolution and which considers the ongoing conflict between scientists and creationists. The work of Charles Darwin is central to the article which summarises his theory of natural selection and also covers creation myths and creationists.

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A Catalyst article looking at the benefits of exercise and how it affects bone structure and hence physical fitness. Furthermore, obesity in Britain is on the rise and so the population is encouraged to do regular exercise, not only for cardiovascular and respiratory health, but also for general well-being. But...

A Catalyst article about what happens as plants grow. During their growth, plants remove compounds of nitrogen, phosphorus and potassium from soil which need to be replaced to maintain the soil’s fertility. For centuries farmers have used organic manures, crop rotation or ploughed in specially grown crops; today...

A Catalyst article looking at how insects are used to provide clues at crime scenes. Forensic entomology is the study of insects and other arthropods in a legal context. It covers many different areas, such as pests in stored food products and insect infestations in human habitations. However, the most high-profile...

A Catalyst article about scientists who are only beginning to understand just how complex and fascinating the relationship between trees, the carbon cycle and climate really is. This article explores how aspects of the GCSE science course relate to the latest research. It also covers the relationship between trees...

A Catalyst article about ants. A colony consists of hundreds, even thousands, of ants working diligently and cooperatively, perhaps to kill and carry a large prey item, build a large nest structure or develop and use road-like networks for foraging. Collectively, colonies of social insects can do amazing things and...

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 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...

This Catalyst article looks at a newspaper report, which carried the headline “It’s life, but not as we know it”, following NASA’s supposed discovery of a ‘second form of life’. The scientific paper, published by the eminent journal Science, even created widespread speculation about the existence of extra-...

A Catalyst article about John Snow who discovered the cause of cholera, how it spreads and how to avoid it. Snow's work is what is now referred to as epidemiology and his persistent investigative work and resulting publications resulted in health authorities using his findings.

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A Catalyst article about homeostasis describing how the process enables birds and mammals to be active on cold days when other species are not.

This article is from Catalyst: GCSE Science Review 2004, Volume 14, Issue 3.

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A Catalyst article discussing how the human body has to handle all sorts of variations, balancing its inputs and outputs, if it is to work efficiently. The article concentrates on one organ, the kidney, and the way it helps to keep things on an even keel through the functions of homeostasis and excretion. What...