B4.1.2.1

Chromosomes

Content

  1. The nucleus of a cell contains chromosomes made of DNA molecules. Each chromosome carries a large number of genes.

In body cells the chromosomes are normally found in pairs.

Describe a practical procedure for a specified purpose. Explain why a given practical procedure is well designed for its specified purpose. Explain the need to manipulate and control variables. Identify in a given context: • the independent variable as the one that is changed or selected by the investigator • the dependent variable that is measured for each change in the independent variable • control variables and be able to explain why they are kept the same. Apply understanding of apparatus and techniques to suggest a procedure for a specified purpose.,

Identify the main hazards in specified practical contexts. Suggest methods of reducing the risk of harm in practical contexts.

Recognise and use expressions in decimal form,

Recognise and use expressions in standard form,

Make estimates of the results of simple calculations,

Use an appropriate number of significant figures,

Make order of magnitude calculations

, Calculate areas of triangles and rectangles, surface areas and volumes of cubes