produce to spores, one is the microspore, which is the male part, and the other is the megaspore, which is the female part. A pollen grain is young male gameophyte enclosed in a protective wall. When fertilization takes place the wall is destroyed and the pollen is transferred to the pistil. Cross-pollination is when a pollen grain is blown to another plant or carried by an animal. Pollen maturation starts when the pollen lands on the stigma and a pollen tube grows toward the ovule. For this to work the proteins of the male and female must be compatible. Only on pollen tube can grow into each ovule but there is normally more than one of them.The ovule must form inside of the megaspore and then develop into an embryo sac. The embryo sac contains eight haploid nuclei: three at the end of the micropyle, one is the egg nucleus, three at the opposite end, and two polar nuclei. When fertilization takes place it may only take an hour after pollination. Some plants like barley however take about two months. Double fertilization also takes place, that is when one sperm fertilizes the egg, and the other forms an endosperm.When the seed and fruit are being developed the wall of the ovule develops a protective seed coat. While this is going on the ovary has turned into a seed. To make sure the seed gets enough food the endosperm keeps dividing so it can keep bringing in food. A little FYI for you is that many fruits do not taste good, they are just for protection of the seed. Once a seed is mature it is ready to be released. Most seeds try to grow away from their parents so they don’t have to battle over food and sunlight. Some seeds are blown in the wind and some are carried by animals. Animals don’t eat plants until they are ripe because they taste bad, thus giving the seed enough time to develop so it can make it through the animal. Some seeds are not even eaten they just attach themselves to animals.When Germination ...
