Reproduction
Plants exhibit an alternation of generations, meaning their life cycles alternate between a haploid and diploid form. Angiosperms, along with out types of plants, produce spores via meiosis. The spores form a gametophyte which in return form haploid gametes, the eggs and sperm. The gametes fuse together to form a diploid zygote. The diploid zygote matures into a sporophyte via mitosis. The process then repeats at the sporophyte releases the haploid spores. Non-flowering plants rely on water or wind for reproduction because the spores must be dispersed and fertilized. This is different than flowering plant because the need for water and wind is no longer there since pollinators do the job of dispersing and fertilizing the genetic material.
Being an angiosperm, flowering plants, Moringa oleifera doesn't rely on spores for reproduction. Because they do not use spores as a means of reproduction, they no longer depend on water for fertilization or wind for dispersal. Flowers are modified leaves which contain petals that serve to attract pollinators. Part of the flower is the perianth which contains the reproductive organs. Stamens produce the pollen, where male gametes are derived and the carpels possess the ovaries with ovules. The ovules are where female gametes form. In order for angiosperms to reproduce, pollination must occur. Pollination is when a nucleus from the pollen (the male gamete) fuses with the nucleus in an ovule (the female gamete). This results in the formation of a seed.
Moringa oleifera possesses 28 chromosomes which during meiosis in both the pollen and ovules are involved in crossing over resulting in genetic variation. A major difference between angiosperms and other seed plants, such as gymnosperms, is that their ovules are completely encases within a carpel. This is an evolutionary advantage because the pollen tube must be able to get through the carpel in order for fertilization to occur. This limits what pollen tubes can enter the ovule ultimately preventing undesirable pollination.
An aspect of flowering plants that is unique is the event of double fertilisation. This is the union of two sperm nuclei. One sperm nucleus fuses with the egg to form a diploid zygote. This is what the embryo develops from. The other sperm nucleus unties with two nuclei that are located in a single cell at the center of the embryo sac. This forms a triploid nucleus in the cell from which the endosperm develops. The endosperm is the tissue within that seed that surrounds and nourishes the developing embryo. After double fertilisation, the ovary will start to swell to form the fruit which is another unique feature to the sexual reproduction of flowering plants.