April Gallery

1985 Portuguese GP

CIRCUITO ESTORIL, PORTUGAL - APRIL 21: Ayrton Senna during the Portuguese GP at Circuito Estoril on April 21, 1985 in Circuito Estoril, Portugal. (Photo by Rainer Schlegelmilch)

© Motorsport Images

F1, Formula 1, Gp, Portrait

Bacterial DNA

False-colour transmission electron micrograph of the bacterium Escherichia coli. The bacterial cell in the centre of the picture was treated with an enzyme to weaken its wall, then placed in water, causing its DNA to be ejected. The DNA is visible as the gold coloured fibrous mass lying around the bacterial shell. The length of the DNA is 1.5 millimetres or 1000 times the length of the cell from which it came. E.coli is usually an harmless inhabitant of the human intestinal tract. It is a major laboratory organism & much of the understanding of genetics has come from the study of this bacterium. Magnification: x7850 at 35mm, x15, 700 at 6x7cm size

© DR GOPAL MURTI/SCIENCE PHOTO LIBRARY

SEM of the bird cherry aphid

Scanning electron micrograph, tinted green, of the bird cherry aphid, Rhopalosiphum padi (also known as Aphis avenae), next to its recently cast off exoskeleton. It is seen feeding on barley (Hordeum vulgare). The exoskeleton is made of inelastic chitin which is shed 5 times before adulthood to allow growth. This species is an economic pest, transmitting two viral diseases, yellow dwarf virus & maize leaf fleck virus, which infect crops such as oats, barley, wheat & maize. Transmission occurs when the aphid inserts its proboscis & feeds on sugar stored in the leaves (as here). Large infestations cause the leaves of a plant to wilt & fall. Magnification: X 14 at 35mm size. Original is BW print Z295/048

© SCIENCE PHOTO LIBRARY.