In a teaching model of wind pollination, 0.5% of the pollen grains reach a stigma…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
In a teaching model of wind pollination, of the pollen grains reach a stigma. A maize cob has silks, and each silk leads to one ovule. Every ovule must receive one grain on average.
- How many grains must be shed for one ovule to get a grain?
- How many grains must be shed for the whole cob?
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. Chance: . Ovules: .
Plan. The grains needed for one ovule are divided by the per cent.
Step 1. One ovule. grains.
Step 2. The cob. grains.
Answer: grains; grains.
Check. of is , which is the number of ovules.
Watch out. This is a model with made-up numbers. It shows why wind-pollinated plants make a great deal of pollen.
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