Questions

DNA - Deoxyribonucleic acid is a type of nucleic acid. The sugar contained in it is called Deoxyribose.

Secondhand smoke is very dangerous and creates serious health risks to you and your family members. 

The troposphere is the lowest layer of the atmosphere and where most clouds are. That means all weather is in the troposphere. Almost all weather occurs in the Troposphere, basically, the lowest layer that goes up to about 10 - 15 kms.

Phage typing is based on the fact that bacterial viruses attack specific cells. Phage typing is a method used for detecting single strains of bacteria. It is used to trace the source of outbreaks of infections. 

Appetite is the desire to eat food, sometimes due to hunger. Appetite is triggered by environmental cues such as the smell or taste of food. Appealing foods can stimulate appetite even when hunger is absent.

A complex sentence is a sentence that contains an independent clause and one or more dependent clauses.

If two clauses are connected with a coordinating conjunction, it's a compound sentence.

If two clauses are connected with a subordinating conjunction, it's a complex sentence.