Introduction
Pollen is well-known as the dusty substance from anthers in flowers. In this web series we will explore the significance of pollen for the reproduction of plants. Furtheron we will discuss the biological background of pollen and the mechanisms behind hay fever, also called pollen allergy, an affection triggered by airborne pollen.
Pollen is the carrier of the male sex cells in plants. Thus, it fulfills a vital function in the sexual reproduction of plants. In the webpage Pollen and Life cycle diagrams illustrate where pollen entails in the reproduction cycle of plants and which similarities and difference exist between the life cycles of plants, animals and humans. The section on Flower and Cone and the item Pollen development focus on the parts of the plant where pollen arises and describes in brief how this process proceeds. The Fertilization, the key issue in which pollen is involved and which eventually leads to seed formation, is explained with drawings and micrographs and with (links to) a number of films and animations. Under Pollination the various means by which pollen is transfered from one plant to the other, i.e. by wind, animals or water, are reviewed by means of examples from nature. How much pollen grains may differ in morphology is shown in Pollen: Shape, Color & Size. Also the occurance of certain species of pollen grains in the air shows great variations overtime, depending a.o. on the flowering period of plants and weather conditions (see Hay fever Plants & Weather). Pollen counting and -calendars provides an overview on how these fluctuations throughout the year are mapped. These data are of importance for people suffering of hay fever, an affection also called Pollen allergy (pollinosis), which touches more than 10% of the population in western countries, and which is directly related to the presence of airborne pollen. Links to various sites with current national hay fever predictions are compiled under Hay fever forecast. Finally, the page called Facts & Links will soon report on various particularities about pollen, for example the etymology of the word "pollen", the use of pollen by man, ways to investigate pollen, and selected literature on the biology of pollen and pollen allergy.
Webpages and photographs:Jan Derksen and Elisabeth Pierson
Drawings: Lidwien van der Horst
Web development: Remco Aalbers
