Questions

Solar radiation instruments may be produced to measure different types of solar energy. When sunlight encounters the Earth's atmosphere, some of it is absorbed or scattered by water vapor, aerosols, clouds, and other air molecules. The radiation which penetrates to the Earth's surface is termed direct solar radiation.

A thermopile pyranometer is a type of actinometer used for measuring solar radiation on a planar surface and it is designed to measure the solar radiation flux density (W/m2) from the hemisphere above within a wavelength range 0.3 μm to 3 μm.

India was re-elected as member of executive board of United Nations Educational, Scientific and Cultural Organization (UNESCO). Executive board is UNESCO's top decision-making body. The election was held at 39th session of General Conference of UNESCO in Paris, France. 

UNESCO is UN association that helps safeguard historical and cultural sites around the world. It is special multi-nation organization, framed in 1945 and situated in France. It promotes literacy and sex education as well as improving gender equality in countries around world. The General Conference determines policies and main lines of work of organisation. Its duty is to set programmes and budget of UNESCO. It also elects members of executive board and appoints, every four years, director-general.

During most of the cell cycle, interphase, the chromosomes are somewhat less condensed and are not visible as individual objects under the light microscope. However during cell division, mitosis, the chromosomes become highly condensed and are then visible as dark distinct bodies within the nuclei of cells. The chromosomes are most easily seen and identified at the metaphase stage of cell division and most of the chromosome images in this gallery are pictures of metaphase chromomosomes.

The cell division takes place in mitosis stage.

All living cells arise from pre-existing cells is one component of the cell theory.

The Cell Theory is one of the basic principles of biology.

The Cell Theory states:

1. All living organisms are composed of cells. They may be unicellular or multicellular.

2. The cell is the basic unit of life.

3. Cells arise from pre-existing cells.