Try it on paper first. A hint, the key idea and the worked solution are here when you need them.
A Chlamydomonas zygote divides by meiosis. Each cell it makes then divides by mitosis times in a row. How many cells are there at the end, and are they haploid or diploid?
The gametophyte () makes gametes; the sporophyte () makes spores by meiosis. Haplontic: the gametophyte is the main plant and the zygote is the only diploid cell (Spirogyra, Volvox). Diplontic: the sporophyte is the main plant (seed plants, Fucus). Haplo-diplontic: both are many-celled (bryophytes with the gametophyte main, pteridophytes with the sporophyte main).
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.
Step 1. Meiosis. One diploid zygote gives haploid cells.
Step 2. Mitosis. Three rounds double the number three times: .
Step 3. Ploidy. Mitosis keeps the chromosome number, so all cells stay haploid.
Answer: cells, all haploid ().
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