Which one of the following combinations of events represents the correct sequence during reproduction in flowering plants ?

The correct answer is D: egg → zygote; zygote → embryo; ovule → seed; ovary → fruit. After fertilisation each structure of the flower turns into the next stage in exactly this way. When a male gamete from the pollen tube fuses with the egg cell inside the ovule, the fertilised egg becomes the zygote. The zygote divides repeatedly to form the embryo. The ovule, which now holds the embryo, develops a tough coat and becomes the seed, while the ovary that contained the ovules ripens into the fruit. Meanwhile the petals, sepals and stamens usually wither and fall. Option A is wrong because the ovule becomes a seed, not a fruit, and the ovary does not turn into an egg. Option B is wrong because it runs backwards: the embryo comes from the egg, and the ovule does not become a zygote. Option C is wrong because the zygote does not become an egg, the embryo does not form an ovule, and a seed never turns into a fruit. Exam tip: egg → zygote → embryo inside the ovule → seed; ovary → fruit.