OCR GCSE Biology Equation Sheet (J247)

Every OCR GCSE Biology equation you need — all 9 formulas by topic. OCR gives no equation sheet for Biology, so all of these must be memorised.

Formulas listed

You must memorise

No sheet given

Memorise only

Cells

Magnification

Memorise

\text{magnification} = \dfrac{\text{image size}}{\text{actual size}}

Real size from image

Memorise

\text{actual size} = \dfrac{\text{image size}}{\text{magnification}}

Surface area to volume ratio

Memorise

\text{SA:V} = \dfrac{\text{surface area}}{\text{volume}}

Body Mass Index (BMI)

Memorise

\text{BMI} = \dfrac{\text{mass (kg)}}{(\text{height in m})^2}

Waist : hip ratio

Memorise

\text{ratio} = \dfrac{\text{waist circumference}}{\text{hip circumference}}

Cardiac output

Memorise

\text{cardiac output} = \text{stroke volume} \times \text{heart rate}

Percentage change in mass (osmosis practical)

Memorise

\%\text{ change} = \dfrac{\text{final} - \text{initial}}{\text{initial}} \times 100

Rate (general)

Memorise

\text{rate} = \dfrac{\text{change}}{\text{time}}

Mean

Memorise

\text{mean} = \dfrac{\text{sum of values}}{\text{number of values}}