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Home > All Images > 1991 > January > 28 Jan 1991

Images Dated 28th January 1991

Choose from 5 pictures in our Images Dated 28th January 1991 collection for your Wall Art or Photo Gift. All professionally made for Quick Shipping.

Pollen from the pot marigold Featured 28 Jan 1991 Print

Pollen from the pot marigold

False-colour scanning electron micrograph of pollen grains of the pot marigold Calendula officinalis. The surface of the pollen grains are covered with tiny barbs, which secure them to the body of an insect for transportation and subsequently to the surface of the stigma at the start of fertilization. One of the furrows, visible here along the length of the lower grain, will produce a slender tube, called a pollen tube, which will grow down to the ovary. Inside the pollen tube, two sperms follow its growth. When the egg is reached, the tube bursts, releasing the sperm, one of which will fertilise the egg. Magnification: x700 at 6x4.5cm size