Matrotrophy associated with vertebrates and especially mammals, matrotrophy is found in 21 of 34 animal phyla, and is fairly common in 11 of those. It has arisen independently in more than 150 clades within Chordata and in more than 140 clades amongst invertebrates. Matrotrophy Matrotrophy is a form of maternal care during embryo development. Some flowering plants supplied the developing embryos for the first stages. The ovule has no stocks and the nutrients are provided by the "mother". In plants, matrotrophy is considered a critical evolutionary development preceding the origin of embryophytes and therefore essential to the evolution of land plants.
Han Chinese subgroups Han Chinese subgroups The sub groups of the Han Chinese people, also known as Sinitic peoples, Chinese dialect groups or just dialect groups, are defined based on linguistic, cultural, genetic, and regional features. The terminology used in Mandarin to describe the groups is: "minxi" ( // "ethnic lineages"), used in Mainland China, or "zuqun" ( //, "ethnic groups"), used in Taiwan. Other than Hui people, which is a classification for Muslims of all backgrounds, no Han subgroup is recognized as one of People's Republic of China's 56 official minority ethnic groups. Mandarin, also known as the Northern dialects, is the