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