The result of double fertilization in angiosperms is the fertilization of two cells in the ovary of a flower, forming both seed and fruit. One sperm cell fertilizes an egg cell to form an ovule that grows into the seed. The second sperm cell fuses with two haploid polar nuclei at the center of the flower's embryo sac to form the endosperm tissue inside the fruit.
To fertilize the flower, pollen adheres to the female stigma, located at the end of the female reproductive structure of the plant or carpel. The pollen grain grows a pollen tube, penetrating through the micropyle, a small pore in the ovum. The sperm passes through the pollen tube to fertilize the two cells. The first is a diploid zygote that forms the seed. The second cell that forms is a triploid, which divides through mitosis and forms the nutrient-rich tissue in the fruit.
Angiosperms are flowering plants. A large majority of organisms from the plant kingdom fit in this category. Except for in extreme habitats, angiosperms thrive in all land biomes and aquatic communities. Angiosperms are an important food source for both humans and animals due to their production of fruit, leaves, stems, seed and roots.Learn More
Pollen is produced in the stamen in angiosperms and is produced in the microsporangiate cones in gymnosperms. The cones that pollen is produced in are usually referred to as male cones or pollen cones.Full Answer >
Though angiosperms and gymnosperms are both seed-producing plants of the Embryophyta subkingdom, they share many more differences than similarities. The most significant regards seed development. While angiosperms produce seeds within an enclosure, the seeds of gymnosperms are not enclosed.Full Answer >
Pollination differs between angiosperms and gymnosperms in that most angiosperms entice animals to carry their pollen from plant to plant, while most gymnosperms rely on the wind carrying their pollen to other plants. There are many wind-pollinated angiosperms and a very few animal-pollinated gymnosperms, however. The methods angiosperms use tend to be more effective at spreading quickly, but gymnosperms, particularly conifers, are generally better adapted to cold or dry environments.Full Answer >
If the water cycle were to stop, lakes, rivers and groundwater sources would dry up, glaciers would disappear and precipitation would stop falling. All freshwater resources would be negatively impacted, and life on Earth would completely cease.Full Answer >