A botany student lists five plants: Cedrus, Mangifera (mango), Ginkgo, Oryza (rice) and Cycas.
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A botany student lists five plants: Cedrus, Mangifera (mango), Ginkgo, Oryza (rice) and Cycas. Sort them into gymnosperms and angiosperms, and give the one feature of the ovules that decides the group.
Need a reminder? The key ideaShow
Gymnosperms have naked ovules on megasporophylls, so their seeds have no fruit. They are heterosporous: male cones make pollen grains (male gametophytes), and each ovule holds a many-celled haploid female gametophyte with archegonia. The wind carries pollen; a pollen tube brings the male gametes. The food store of the seed is the haploid female gametophyte.
The worked solution
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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.
Step 1. The deciding feature. In gymnosperms the ovules lie open on sporophylls. In angiosperms the ovules lie inside an ovary.
Step 2. Gymnosperms. Cedrus (deodar), Ginkgo and Cycas bear naked ovules and seeds.
Step 3. Angiosperms. Mango and rice flower, and their seeds form inside fruits.
Answer: gymnosperms: Cedrus, Ginkgo, Cycas; angiosperms: mango and rice. The deciding feature is whether the ovules are enclosed in an ovary.
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