Pollen collecting (Teacher Support)

Why study pollen?

Pollen is crucial for plant reproduction as it carries the male reproductive cells from one flower to another for fertilising eggs. Once fertilisation has taken place, a seed begins to form. Pollen is produced in humongous quantities and at certain times of the year forms yellowish clouds above pine forests and can be seen as a creamy yellow scum on puddles.

Pollen is moved from one flower to another either by wind or by animals such as insects, birds and bats.

Relates to: student's Pollen Collecting Activity

Pollen Collecting Activity Sheet

Answers (more detail than expected from students)

1. Stamens can be found deep inside the body of some flowers, near the opening, or poking out of others. Frequently in wind pollinated flowers the stamen hangs out of the flower with the anthers dangling loosely on the end of the filament. (Wherever they are found, they are positioned for most effective transport of pollen from one flower to another either by animals or the wind.)
2. Yes, wind pollinated flowers produce huge quantities of smaller pollen grains for carrying on the wind. Pollen grains are usually larger and produced in smaller quantities in insect pollinated plants. Examples of colours: cream, yellow, orange, brick red, bluish black, etc. Examples of shapes (viewed in 2-dimensions under a microscope) include: triangular, oval, round, bumpy, spiky, lobed, etc. Search in Google Images using 'pollen shapes' to see examples of pollen grains. Note how in reality pollen grains are three dimensional.
3. Caught on their body hairs, feet and mouthparts. No, insects don't transfer the pollen on purpose.
4. Pollen is needed for plant reproduction since it carries the male reproductive cells from one flower to another for fertilising the eggs. Once fertilisation has taken place, seeds begin to form.
5. Seeds would not be produced. Since land-based habitats need seeds and the plants they grow into, they would in turn collapse, with dire consequences for the web of life, to which humans belong.
6. Pollination vectors have evolved to pollinate particular plants. Without them, those plants would not replace themselves and so could eventually become extinct.

Picture credits: Thumbnail image (CC BY-SA Josef Reischig).