The human life cycle may be said to begin with fertilization and then proceed through prenatal growth and development, birth, postnatal growth and development, maturity, senescence, and death. While you might think of child development as something that begins during infancy, the prenatal period is also considered an important part of the developmental process. Prenatal development is a time of remarkable change that helps set the stage for future psychological development. The brain develops over the course of the prenatal period, but it will continue to go through more changes during the early years of childhood. The process of prenatal development occurs in three main stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is known as the embryonic period, and the time from the ninth week until birth is known as the fetal period.

When at least two electrodes are dipped into an electrolyte and connected by an external electrical conductor, an electric current flows and chemical reactions occur in the half cells

Bimolecular reactions – gaseous and liquid states. Quasi equilibrium and steady state approximation theory of reaction rates. Reaction mechanisms.

Aldehydes and ketones are in equilibrium with their enol isomers.

Nutrients are essential life chemical elements (About 16 elements). Macronutrients:-Compounds required in great quantities

Sun's energy is harvested by plants and stored as chemical energy through photosynthesis.

The diversity of climates and landforms leads to great diversity of vegetation types in E.A. .Vegetation is influenced by eq uator, relief and altitude especially by Mt. Kenya, Kilimanjaro and Ruwenzori Mountains that are over 5000m high.

Communities associated with freshwater lakes, river valleys and areas that are permanently or temporarily waterlogged. Waterlogging is a result of drainage impediment. These communities are ecotones between dry land and open water. Wetlands are highly productive. They are species rich as they draw them from the adjacent ecosystems.

Evolution is the change over time. It leads to diversity , structural complexity and adaptive nature of plants. Organic evolution is a series of transformations in the genetic material of a population over time .The primary cause of evolution is natural selection in response to the changing environmental interactions

Nomenclature is the correct naming of plants according to specified rules. Plants were known by their common names during the pre-scientific times. The use of common names however are limited to geographical locations or cultures.