Water hyacinth covers the whole surface of water bodies and causes other surface and underground plants to die due to lack of sunlight. The increased organic content causes microbes growth that consumes oxygen in the decomposition of organic matter causing fishes to die due to oxygen scarcity. Asexual reproduction does not include meiosis and syngamy and the progeny is genetically identical to the parent. i.e., clone. Zoospores are flagellated microscopic asexual bodies of algae. Statement A is incorrect as an axillary bud in these plants give rise to plantlet; not the internode.