life cycles in plants

Death is the final termination of the life activities. Every living organism has a life cycle involving its birth, growth and death. The duration of life between the birth and death of an organism, represents its life span. This ranges from ..

The eggs of some normally sexually reproducing animals can be induced by artificial means to develop parthenogenetically. The stimuli inducing artificial parthenogenesis are salts, weak acids, organic solvents, urea, sucrose and physical stimuli like temperature, electric shock or mere shaking. Par..

. The diploid zygote develops into an embryo which remains enclosed within the ovule. The ovule then transforms itself into a seed. The seed remains attached to the megasporophyll and is not enclosed by a fruit. The ripe and dry seeds are shed. Under suitable conditions the seeds germinate and deve..

Thermal Pollution results from power plant and factory discharges of water used for cooling purposes. These raise the temperature of a body of water. Nuclear power plants use vast quantities of water for coolants, returning the water somewhat heated. The increased temperatures ..

Summary - The basis of life on earth is atmospheric cover on earth and natural cycles like carbon, oxygen, nitrogen and hydrological cycles. Atmosphere is evolved in its present form due to sunlight and rotation of earth on its axis. Many environmental changes like cha..

Summary - Wild life and forests make our biotic resources Wild life maintains food chains and natural cycles, has immense value as gene banks for breeding programmes. Although creation and extinction of species is a natural phenomenon, elimination of species has become..

Nitrogen forms nearly 78% of the volume of air. Earlier, the useful significance of nitrogen was not known and it was considered to be inactive. At that time, nitrogen was considered important only because it was known to moderate the processes of respiration and combustion, by diluting the effect ..

The basis of life on earth is atmospheric cover on earth and natural cycles like carbon, oxygen, nitrogen and hydrological 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..

These are protozoans which occur as endoparasites in different groups of animals. They lack locomotor structures. The body has a tough covering called cuticle and a single nucleus. Asexual reproduction occurs by multiple fission. Sexual reproduction involves anisogamy. Life cycle..