Reaction of the pupil to light Illustration Play

Reaction velocity and substrate concentration Illustration Play

Recommended daily protein intake according to sex and age Illustration Play

Record tides Illustration Play

Red blood cells Illustration Play

Referred pain regions Illustration Play

Reflex arc Illustration Play

Regulation of blood volume during haemorrhage Illustration Play

Regulation of the synthesis of enzymatic proteins Illustration Play

Regulatory region Illustration Play

Regulatory sequences Illustration Play

Relationship between maternal age and risk of Down's syndrome Illustration Play

Relationship between the period of revolution and the orbital radius Illustration Play

Reproduction in lichens Illustration Play

Rescue dog Illustration Play

Research into photosynthesis - conclusions Illustration Play

Resting form in protists Illustration Play

Restoration of saprophytic flora after antibiotics treatment Illustration Play

Restriction maps Illustration Play

Retina Illustration Play

Retracing prehistoric times from limestone Illustration Play

Reversible and irreversible processes Illustration Play

Reversible and irreversible processes Illustration Play

Rhizodermis Illustration Play

Rhombic sulphur (alpha-sulphur) Illustration Play

Risk factors for cardiovascular disease Illustration Play

Rods and cones Illustration Play

Root Illustration Play

Roses Illustration Play