Year 9 · Spring Second Half

Biology

3 lessons from 1 unit.

Unit B10 · lessons 1 to 3 of 5

Every one of your characteristics arrived from somewhere, and most of them arrived twice. This unit starts with the variation you can measure in a room full of people, works down through chromosomes and genes to the molecule the instructions are written in, follows how that structure was worked out, and ends with the question of what makes two organisms the same species at all.

01Variation: continuous and discontinuousInvestigationLine a class up by height and you get a smooth ramp with no gaps. Line the same class up by blood group and you get four piles and nothing in between. The difference is not what you measured with.Open this lesson
02Chromosomes, genes and DNAModelFour words that people use as though they meant the same thing — nucleus, chromosome, gene, DNA — and they are four different levels of one structure, nested inside each other like the levels of organisation you already know.Open this lesson
03How we worked out DNA's structureInvestigationNobody has ever seen a DNA molecule. Its structure was deduced from a photograph of scattered X-rays, a table of chemical ratios, and a set of metal models built on a bench in Cambridge.Open this lesson

Back to all three sciences this half term The whole KS3 Biology course