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.
Subgroups of cyclic groups cyclic, and that has a distributive lattice of subgroups, but that is not itself cyclic. Subgroups of cyclic groups In abstract algebra, every subgroup of a cyclic group is cyclic. Moreover, for a finite cyclic group of order "n", every subgroup's order is a divisor of "n", and there is exactly one subgroup for each divisor. This result has been called the fundamental theorem of cyclic groups. For every finite group "G" of order "n", the following statements are equivalent: This statement is known by various names such as characterization by subgroups. (See also cyclic group for some characterization.) There