angiosperm life cycles

. Each stamen has an anther and a filament. The anther produces pollen grains containing the highly reduced male gametophyte . The carpels represent megasporophyll. They enclose ovules containing the egg cell which with the associated cells represent the female gametophyte . A characteristic featur..

Angiosperms exhibit a great diversity in form, size, structure and life span of the plant body. Based on the duration of life span, angiosperms are classified into annuals, biennials and perennia..

When all the hydrogen gets exhausted, fusion stops and as a result the internal pressure, which keeps the star from collapsing under its high gravitational force decreases and the core contracts under its own gravity. However, the hydrogen in the outer shell fuses to helium and releases energy. Bu..

Water Cycle or Hydrological Cycle - Water is an indispensable commodity of life. Water determines the distribution, structure and function of organisms in the ecosystem. Water occurs in three phases - solid, liquid (ice/snow) and gaseous (water vapour). In liquid phase..

Earth is the source of matter for all living organisms, as they require several (about 40) elements for their growth and life processe..

Oxygen Cycle - Oxygen is another essential element for living organisms. It is present in large quantities (20.95% v/v) in the atmosphere and is also seen in bound state in water and as oxides and carbonates in rocks. Dissolved oxygen in water is the source of oxygen for aquatic organisms..

Biogeochemical Cycles - Earth is the source of matter for all living organisms, as they require several (about 40) elements for their growth and life processes. Some elements and their compounds have an important role in the living protoplasm and are required in large amounts. T..

Nitrogen Cycle - Nitrogen is an essential constituent of animal and plant matter as it forms proteins, which are the building blocks of life. The ultimate source of nitrogen is atmospheric nitrogen but neither plants nor animals are capable of assimilating free nitrogen. Thus th..

The characteristics of organisms Life cycles of organisms Organisms and environment..

The life cycle of a star begins with the accretion of hydrogen and helium gas at -173 o C into smaller dense clouds, which contract under their own gravity. This dense cloud of gas contracting under its own gravity is called a Protostar. A cloud of gas from which a star is..