Questions

The prostate gland is a walnut-sized structure that is located below the urinary bladder in front of the rectum. The prostate gland contributes additional fluid to the ejaculate. Prostate fluids also help to nourish the sperm. The urethra, which carries the ejaculate to be expelled during orgasm, runs through the center of the prostate gland.

Phototropism is the ability of a photosynthesizing organism, to grow directionally in response to a light source. It is very common in plants, but can also occur in other organisms such as fungi.

Example :: Sunflower

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.

There are approximately 6 trillion miles in a light-year, so the distance we need to go is 6 trillion miles / light-year times. 4 light-years is equal to 24 trillion miles. So, this whole would take 1.2 billion hours. There are 24 hours a day and 365.25 days per year, so this time in years is 137 thousand years.

Based on conventionality in deriving energy, energy sources could be classified as

Conventional ::

coal, oil, hydro, nuclear, etc... sources which can be used up or exhaustible.

(and)

Non - conventional ::

solar, wind, tidal, geothermal, biogas, etc... sources which are not exhausted.

Among the given options, Geothermal energy is the alternative energy source among all the choices that are given in the question, that is exhaustible.