Download Unit 9 Completed Vocabulary - WAHS

Unit 9 Vocabulary
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Section 1
transformation – process in which one strain of bacteria is changed by a gene or genes
from another strain of bacteria.
bacteriophage – a virus that infects bacteria.
nucleotide – monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group,
and a nitrogenous base.
base pairing – principle that bonds in DNA can form only between adenine and thymine
and between guanine and cytosine.
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Section 2
chromatin – granular material visible within the nucleus; consists of DNA tightly coiled
around proteins.
histone – globular protein molecule around which DNA is tightly coiled in chromatin.
replication – copying process by which a cell duplicates its DNA.
DNA polymerase – enzyme that “proofreads” new DNA strands, helping to ensure that
each molecule is a nearly perfect copy of the original DNA.
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Section 3
messenger RNA (mRNA) – RNA molecule that carries copies of instructions for the
assembly of amino acids into proteins from DNA to the rest
of the cell.
ribosomal RNA (rRNA) – type of RNA that makes up the major part of ribosomes.
transfer RNA (tRNA) – type of RNA molecule that transfers amino acids to ribosomes
during protein synthesis.
transcription – process in which part of the nucleotide sequence of DNA is copied into a
complementary sequence in RNA.
RNA polymerase – enzyme similar to DNA polymerase that binds to DNA and
separates the DNA strands during transcription.
promoter – region of DNA that indicates to an enzyme where to bind to make RNA.
intron – intervening sequence of DNA; does not code for a protein.
exon – expressed sequence of DNA; codes for a protein.
codon – three-nucleotide sequence on messenger RNA that codes for a single amino
acid.
translation – decoding of a mRNA message into a polypeptide chain.
anticodon – group of three bases on a tRNA molecule that are complimentary to an
mRNA codon.
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Section 4
mutation – change in a DNA sequence that affects genetic information.
point mutation – mutation that affects a single nucleotide, usually by substituting one
nucleotide for another.
frameshift mutation – mutation that shifts the “reading” frame of the genetic message by
inserting or deleting a nucleotide.