This Catalyst article details how the genome of a plant called Arabidopsis has been unravelled so that this species can act as a model in genetic studies. Arabidopsis thaliana is a model species like the fruit fly Drosophila, yeast, and the bacterium Escherichia coli.  Scientists...

This Catalyst article looks at sexual selection, a form of natural selection, and the role it plays in the evolution of many organisms. The article is from Catalyst: Secondary Science Review 2014, Volume 24, Issue 4.

Catalyst is a science...

This Catalyst article looks at the production of rice, which is a staple food for billions of people. It describes how crop scientists have identified varieties of rice with favourable characteristics, such as flood resistance, and are using them to develop crops with increased yield. Such crops may help to...

This edition of the Computing at School newsletter focuses on teaching computing in primary schools, and contains articles covering:

*Pedagogy of computing in primary schools

*National curriculum programme of study

*Game design in the primary classroom

*Primary – secondary transition...

This introductory article shows working examples of basic Python programs. It includes:

• Printing to the screen
• Comments
• Simple arithmetic
• Using variables
• Strings and string arrays
• For and While loops
• Random numbers from the Random library
• Creating a...

This Catalyst article explains how studying sand can reveal both the geological and biological history of a local environment as sand varies from place to place. Sand from near a copper smelter can contain grains of copper; grains can contain worm trails from microscopic worms living in the ocean. Even the grains...

This introduction to programming in Scratch uses a trivial example to demonstrate simple audio and animation. It is written for Scratch 1.4 but can be easily adapted for later versions. ...

This short practical guide shows how to implement a bubble sort algorithm in Scratch. The procedure is easy to follow, and can be used in conjunction with theory or unplugged activities to aid...

This simple game is an engaging way to extend learning in Scratch. It uses fairly simple scripts running in parallel to detect collisions and move sprites, which have been designed in the Scratch environment. It could be used a basis for other similar ‘scrolling’ games. 

This activity is an introduction to writing programs that can handle errors. It also helps students to understand number bases, by guiding them through the writing of a ‘base converter’ program.

Suitable for students throughout secondary computing, including those studying at an advanced level, this exercise introduces the Heap Sort and explores why it is more efficient than the Bubble Sort in another Scratch Patch article. Students learn about tree data structures, including the correct terminology for...

This game-writing activity using Scratch will bring back youthful memories for some! It provides...

This practical guide to creating a simple game is aimed at those new to programming with Scratch...

Combining some fundamental physics with trigonometry and computer programming, this guide helps students to create a simulation of the projectile motion of a cannon ball. The concepts are all briefly explained, and the program introduces some clever mathematics as well as game elements, such as collision detection...

This project, exploring basic encryption, is a useful introduction to data security as well as iterating through strings to manipulate them. The program create a ‘substitution cipher’, one of the most basic forms of encryption. It also demonstrates that, for more complex chained commands, Scratch becomes rather...