Which of the following is most directly responsible for water's unique properties? A It contains oxygen atoms.
B It contains hydrogen atoms.
C It is an ionic compound.
D It forms hydrogen bonds.
E It is nonpolar.

Water molecules are polar, so they form a hydrogen bond(s). This gives water unique properties,  for example a relatively high boiling point, high specific heat, cohesion, adhesion and density.

Explanation:

image result for describe the various types of gene mutationsghr.nlm.nih.gov

the types of mutations include: missense mutation: this type of mutation is a change in one dna base pair that results in the substitution of one amino acid for another in the protein made by a gene. nonsense mutation: a nonsense mutation is also a change in one dna base pair.

explanation:

the correct answer is 4) heat and pressure

metamorphic rocks arise from transformation of existing rocks types, in a process called metamorphism. during metamorphism the original rock(prolith) change into metamorphic rock by heating (150-200c) and pressure of more than 1000 bar. the original rock can be sedimentary, igneous, or existing metamorphic rock.