Questions

Like commas, semicolons indicate an audible pause — slightly longer than a comma's, but short of a period's full stop.

Rules for Semicolon ::

1. A semicolon can replace a period if the writer wishes to narrow the gap between two closely linked sentences.

2. Use a semicolon before such words and terms as namely, however, therefore, that is, i.e., for example, e.g., for instance, etc., when they introduce a complete sentence. It is also preferable to use a comma after these words and terms.

3. Avoid a semicolon when a dependent clause comes before an independent clause.

4. Use a semicolon to separate units of a series when one or more of the units contain commas.

Hence according to rule no. 2) option (C) He ate; however, he didn't sleep is correctly puctuated with a semicolon.

Plants grow in size both in height and in girth. Enlargement of cells already present cannnot contribute much to the growth. Only addition of more and more cells could increase the size of the plant considerably.

Phosphorescence is a phenomenon associated with an algal division called euglenophytes. 

Phosphorescence is a phenomenon when an object is capable of releasing photons of light at a longer wavelength in response to absorbing light of a shorter wavelength. The object releasing the light only releases the light after some time has passed since it absorbed the light of a short wavelength.

Euglenophytes are single-celled plant-like protists that have no cell wall.

It is using a router to answer ARP requests. This will be done when the originating host believes that a destination is local, when in fact is lies beyond router.

Though this is essentially a Committee of the House of the people (Having 15 members from that house), by an agreement between the two houses, 7 members from the other Houses are also associated with this committee, in order to strengthen it.

Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms activities.

Labyrinth which is part of the ear is the main organ of balance in the human body.