colourised sem image of atropa pollen, showing the hard coat which protects the sperm cells during the movement from stamens of producing flower to the pistil of the receiving flower. atropa is a genus of the nightshade family. - oocyte sem stock pictures, royalty-free photos & imagesColourised SEM image of Atropa pollen, showing the hard coat which protects the sperm cells during the movement from stamens of producing flower to the pistil of the receiving flower. Atropa is a genus of the nightshade family.Human Egg