MOLECULAR BIOLOGY EXAM: LATEST A+ QUESTIONS AND ANSWERS BREAKDOWN

MOLECULAR BIOLOGY EXAM: LATEST A+ QUESTIONS
AND ANSWERS BREAKDOWN
nucleic acids
DNA and RNA are examples; so called because they are found in the nucleus and possess many
acidic phosphate groups.
adenine
one of the four aromatic bases found in DNA and RNA; a purine that pairs with thymine (in
DNA) and uracil (in RNA).
guanine
one of four aromatic bases found in DNA and RNA; a purine that pairs with cytosine.
cytosine
one of four aromatic bases found in DNA and RNA; a pyrimidine that pairs with guanine.
thymine
one of four aromatic bases found in DNA and RNA; a pyrimidine that pairs with adenine.
genome
all the genetic information in an organism; all of an organisms chromosomes.
chromosome
a single piece of double-stranded DNA; part of the genome of an organism.
DNA gyrase
a prokaryotic enzyme used to twist the single circular chromosome of prokaryotes upon itself
to form supercoils.
histones
globular proteins that assist in DNA packaging in eukaryotes. histones form octamers around
which DNA is wound to form a nucleosome.
nucleosome
a structure composed of two coils of DNA wrapped around an octet of histone proteins.
nucleoside
a structure composed of a ribose molecule linked to one of the aromatic bases.