Questions

One who copies from other writers is called Plagiarist.

It is a host that has a multiple network interfaces and that requires multiple IP addresses is called as a Multi-homed Host

Plant cell walls are mostly made up of the molecule cellulose. Cellulose is a polysaccharide, a complex sugar made of long chains of glucose.

The cell wall must be made of thick and strong material as it provides the structural shape of the plant and protection from insects and microorganisms.

DNA is not a single stranded and does not have amino acids. Hence options, b & C are eiminated. Dna is a double helix structure containing nucleobase—either cytosine (C), guanine (G), adenine (A), or thymine (T)—as well as a monosaccharide sugar called deoxyribose and a phosphate group. 

Karst topography is created by the chemical weathering of the rocks such as limestone, dolomite etc...