Ovule number of Osmunda japonica

When a flower is pollinated and fertilized, the ovary develops into fruit and the ovule develops into a seed. So the number of fruits depends on the number of ovaries, and the number of seeds depends on the number of ovules. Therefore, a full kidney bean fruit has five seeds, and the ovary and ovule needed for the formation of this kidney bean are 1 and 5 seeds respectively. Because angiosperms have a unique double fertilization function (that is, after pollination, pollen germinates into pollen tubes under the stimulation of pistil stigma mucus. When it reaches the ovule in the ovary, the front end of the pollen tube breaks, releasing two sperm, one of which combines with the egg cell near the micropyle to form a fertilized egg, and the other combines with the polar nucleus in the center to form a fertilized polar nucleus, thus completing the double fertilization process. ), that is, each seed needs two sperm to complete a double fertilization, so five seeds need five pollen grains and 10 sperm.

So the answer is: 5; ? 10; 1; five