BIO 110 test 4 chapter 12, 13
frameshift mutations result from the
insertion or deletion of one or two base pairs
in DNA replication, the lagging strand
is synthesized as a series of Okazaki fragments
The information encoded by the DNA is specified by the
nucleotide sequence of the DNA molecule
differences in the sequence of ______ in the gene result in differences in the sequence of ______ in the protein
nucleotides; amino acids
because a newly synthesized DNA molecule contains _______, the replication process is said to be semiconservative
one parental strand and one new strand
these noncoding sequence located with coding regions of ______ genes are called ______
only eukaryotic; introns
DN replication occurs
prior to cell division
a 5' cap
protects mRNA from degradation
what type of RNA makes up a portion of the ribosome?
rRNA
______ occurs in nucleus and ______ occurs in the cytoplasm
replication and transcription; translation
because there are 64 codons specifying 20 amino acids and three stop codons a mutation could result in no change in amino acid sequence. this is called a
silent mutation
RNA is ______ and contains the nitrogenous base ______, which id absent in DNA
single stranded; uracil
in replication, once the DNA strand have been separated, reformation of the double helix is prevented by
single-strand binding proteins
individuals with mutations in excision repair enzymes may suffer from _______ due to unrepaired DNA damage caused by ________
skin cancer; the sun's UV rays
the two molecules that alternate to form the backbone of a DNA molecule are
sugar and phosphate
tRNA molecules are able to act as adapters between amino acids and mRNA during translation because
tRNA can bind to both mRNA and an amino acid
_______ the ends of eukaryotic chromosomes, shorten with every cell division
telomeres
how is bacterial chromosome replicated?
the circular DNA molecule is replicated from one origin of replication bidirectionally
how is the four-letter language of nucleic acids converted into the twenty-word language of amino acids?
the four nucleic acid bases combine in three-letter sequences that different amino acids
in essentially all organisms, the AUG codon codes for
the initiation of translation
during translocation, the movement of the ribosome repositions the tRNA linked to the growing polypeptide chain to the ______ site, there by vacating the ______ site for the arrival of a new aminoacyl tRNA
P; A
transcription and translation of a gene composed of 30 nucleotides would form a protein containing no more that ______ amino acids
10
during transcription nucleotides are added to the ______ end of the ______ strand
3' ; RNA
what mRNA sequence for a strand of DNA reading 5'- CCGTACT- 3'
3'- GGCAUGA- 5'
one of the MRNA codons specifying the amino acid leucine is 5'-CUS-3'. the corresponding anticodon is
3'-GAU-5'
which of the following nucleotide sequences represents the complement to the DNA strand 5'-AGATCCG-3'
3'-TCTAGGC-5'
at the 5' end of DNA strand, the phosphate is attached to the
5' deoxyribose carbon
in replication a ______ is copied and in transcription a ______ is copied
chromosome; gene
hydrogen bonds can form between guanine and ______, and between adenine and ______
cytosine; thymine
a stretch of DNA that codes for a protein can be called a
gene
production of a polypeptide using the information in mRNA is called
translation
What causes the unwinding of DNA double helix?
DNA helicase
okazaki fragments are joined together by
DNA ligase
when a mutation occurs during DNA replication, ______ replaces the incorrect nucleotide with correct one after the mismatched nucleotide has been removed
DNA polymerase
which of the following adds new nucleotides to a growing DNA chain
DNA polymerase
what is the modern definition of a gene?
a DNA sequence that encodes a specific RNA or protein product
a polyribosome is
a complex composed of several ribosomes and plus an mRNA transcript
during protein synthesis, ribosomes
attach to the mRNA molecule and travel along its length to produce a polypeptide
two chains of DNA must run in _______ direction(s) and must be _______ if they are to bond with each other
antiparallel; complementary
why is only one strand of DNA transcribed into mRNA?
because transcribing both DNA strands would produce different amino acid sequences
how is a single strand of DNA able to serve as a template for the synthesis of another strand?
both the pairing of nucleotides and the breaking of hydrogen bonds
which of the following statements concerning DNA is false? a) the structure of DNA can be described as a double helix b) DNA is a polymer of nucleotides c) purines and pyrimidines are complimentary d) the sugar present in DNA is ribose e) the two chains of DNA are antiparallel
d) the sugar present in DNA is ribose
the sugar in the backbone of DNA is
deoxyribose
a nucleic acid was analyzed and found to contain 32 percent A, 18 percent G, 18 percent C, and 32 percent T. the nucleic acid must me
double stranded DNA
the codon is found in the
mRNA
what is made from DNA
mRNA, tRNA, rRNA
primase is the enzyme responsible for
making short strand of RNA at the site of replication initiation
a mutation that replaces one amino acid in a protein with another is called a ______ mutation
missense
a ______ mutation results in the conversion of a codon specifying an amino acid to a termination codon
nonsense
RNA synthesis is also known as
transcription