A gardener watches four events. A bee carries pollen from the anther of a rose flower to the stigma…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A gardener watches four events.
- A bee carries pollen from the anther of a rose flower to the stigma of another flower on the same bush.
- A Viola flower never opens, and its own pollen falls on its own stigma.
- The wind carries maize pollen to the silks of a different maize plant.
- A butterfly carries pollen from one flower to another flower of the same plant, and the pollen is genetically identical to the plant.
Name the kind of pollination in each case. Which of them brings genetically new pollen?
Need a reminder? The key ideaShow
Autogamy is pollination within one flower. Geitonogamy is pollination between flowers of the same plant. Xenogamy is pollination between flowers of different plants. Cleistogamous flowers never open and always self-pollinate. Wind-pollinated flowers have light pollen, a feathery stigma and one ovule in each ovary. Animal-pollinated flowers are colourful and make nectar.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. Four events.
Plan. Decide the source of the pollen in each.
Step 1. Case (a). Another flower of the same bush: geitonogamy.
Step 2. Case (b). A closed flower, the pollen falls on its own stigma: autogamy, from a cleistogamous flower.
Step 3. Case (c). A different plant: xenogamy.
Step 4. Case (d). Another flower of the same plant: geitonogamy.
Answer: (a) geitonogamy, (b) autogamy, (c) xenogamy, (d) geitonogamy. Only (c) brings genetically new pollen.
Watch out. The agent does not decide the kind. The source of the pollen does.
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