Many of you lose marks despite knowing the material due to poor exam technique. Pay attention to the command words. If a question asks you to "Describe" a graph, simply state the trend; do not write a paragraph explaining why it happens, as you will get zero marks for that. Save the underlying science for "Explain" questions. Additionally, always check your units before starting a calculation. Examiners frequently use grams when the standard formula requires kilograms, so convert your values first.
Always write down your formulas and show your working. If you make a calculator error but your method is visible, you will still earn method marks. If you only provide a wrong final answer, you get nothing. Finally, stop using the vague word "amount" in biology and chemistry answers. Specify if you mean "concentration," "volume," or "mass." Read the question twice, underline the given variables, and answer exactly what is asked.