life cycles activities

The Universe..

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. These nutrients are called 'macro n..

Water is an indispensable commodity of life. Water determines the distribution, structure and function of organisms in the ecosyste..

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 it is vital for the existence of life on this..

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 nitroge..

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. Oxygen in the Ozone lay..

The nitrogen cycle is complex as it depends on the activities of various bacteria. Nitrate in the soil is built up by plants into protein which is then passed on to animals, which eat the plants. The nitrogen from the protein is returned to the environment as ammonia (ammonifica..

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..