life cycles

The Universe..

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..

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

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..

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..

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..

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..

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

The Life of a Star - 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 o..

At about the age of 10 to 13 years, the ovaries of females are stimulated by the follicle stimulating hormone (FSH) of the pituitary. This is called the onset of puberty and is accompanied by release of hormones oestrogen and progesterone. These hormones control the production of ova or eggs and a..