問題一覧
1
Forensic investigators are working at the scene of a murder. They discover semen, saliva, blood, and hair that was left behind by the murderer. From which of these might the investigators isolate the murderer’s DNA?
all of these
2
If one strand of DNA reads A T T A C G C C, what will the complementary strand read?
T A A T G C G G
3
Is it possbile to share the same dna with someone?
yes, only if they are your identical twin
4
what is the function of dna?
contains the instructions needed for an organism to develop, survive and reproduce.
5
how is dna organized in cells?
packaged inside microscopic nuclei
6
how is dna copied in living cells?
dna molecule sperates into two strands and produces two new complementary strands following rules of base pairing
7
how can dna be amplified for forensics?
polymearse chain reaction (PCR)
8
how does dna profiling make use of genetic variation in dna sequences?
the number of times a sequence repeats varies from person to person, and this variation can be used to tell people apart
9
a genome is...
a complete set of genetic instructions encoded in all the chromosomes of an organism
10
what are three components of a nucleotide?
a phosphate group, a five-carbon sugar, a nitrogenous base
11
human sex chromosomes...
23 pairs, 1st 22 pairs are known as autosomes, 23rd pair determines sex, XX= female, XY= male
12
what do the two types of sugars determine?
which type of nucleic acid is being used
13
what are the two groups of nitrogenous bases?
purines, pyrimidines
14
what bases are in the purine group?
adenine, guanine
15
what bases are in the pyrimidines group
cytosine, uracil, thymine
16
where are uracil bases present?
only in ribonucleotides
17
where are thymine bases only present in?
only in deoxyribonucleotides
18
how are dna strands held together?
hydrogen bonding
19
the two strands of the double helix DNA are...
anti-parallel
20
what form the backbone of a nucleic acid?
sugar & phosphates
21
bases form...
internal "rungs" in dna structure
22
sugar phosphates are
directional
23
how is dna packaged?
inside microscopic nuclei with the help of histones
24
what is dna replication?
cells making identical copies of dna molecules
25
why do we need dna replication?
for growth, repair, and regeneration of tissues in living organisms
26
1st step of dna replication?
hydrogen bonds holding base pairs together are broken and the helix is unwound by helicase
27
2nd step of dna replication?
dna polymerase adds complementary nucleotides using rules of base pairings
28
3rd step of dna replication?
new nucleotides are complementary to old nucleotides
29
4th step of dna replication?
after replication, two copies of the original dna exist. each molecules consists of an original strand and a new strand
30
dna replication is...
semi conservative
31
the specific sequence of nucleotides along a strand of dna is
unique to each individual
32
what is polymerase chain reaction?
a laboratory technique used to amplifiy dna sequences
33
what does pcr do?
mimics what happens in cells when dna is copied prior to cell division, but is carried out in controlled conditions in a laboratory, allows to obtain millions of copies of dna from inute quantity of dna, amplifies a specific sequence of dna
34
you are hired as a research assistant to help determine the genome of a wild onion plant. at the end of this project, you expect to have the:
sequence of all its DNA
35
human DNA is located in the _____ and its distributed among ____ individual chromosomes.
nucleus; 46
36
what are the four nucleotide bases that make up the "rungs" of the nucelotide ladder of DNA?
adenine, thymine, guanine, cytosine
37
what is the correct pattern of nucleotide base pairing?
adenine-thymine; guanine-cytosine
38
you have a segment of DNA with a nucleotide sequence reading AATAGC on one strand. which nucleotide sequence would match it on the opposite strand?
TTATCG
39
the process of DNA replication requires
all of these
40
the original strand of DNA used for DNA replication is known as the
template strand
41
helicase is an enzyme that
breaks the hydrogen bonds between nucleotide base pairs to unwind the DNA double helix
42
what is meant by "semiconservative" replication?
each newly replicated strand of DNA consists of one original strand and one newly formed strand
43
why is heating a first step in PCR amplification of extracted DNA?
it permits hydrogen bonds between DNA strands to dissociate
44
Anticodon is the term applied to —
the part of the tRNA that interacts with the codon
45
Unripe black walnuts contain a compound, juglone, that inhibits RNA polymerase. With which process would juglone most likely interfere?
transcription
46
All of the following are transcribed directly from DNA except—
proteins
47
Which of the following involves movement of an "amino acid-tRNA" from the A site to the P site?
elongation of translation
48
A protein has an amino acid sequence leucine-alanine-serine. The amino acids are represented by the mRNA code UUGCGAAGU. What is the corresponding DNA template strand for this sequence?
AACGCTTCA
49
in your body what kind of molecule acts as an enzyme, helps to transport other molecules, and gives structural support in mnay cells?
protein
50
the shape of a protein is determined by the sequence of its
amino acids
51
the coding sequence of a gene is the portion of the DNA that
specifies teh shape and fucntion of a protein
52
to produce a human gene in goat's milk one would fuse
regulatory elements from a protein produced in goat's milk to the coding region of the human gene
53
the codon for the amino acid methionine is AUG. What anticodon on a tRNA molecule will match methionine's codon?
UAC
54
CAU is a _____ which could be found in _____.
codon, mRNA
55
what RNA molecule would be made from the DNA template CGTTACG?
GCAAUGC
56
transcription builds ___, whereas translation builds ____.
RNA; proteins
57
if a DNA coding region has 12 nucleotides, how many amino acids could it encode?
4
58
what is the difference between eukaryotic and prokaryotic gene transcription?
in the eukaryotes, it occurs in the nucleus; in prokaryotes, it occurs in the cytoplasm
59
a gene is
a section of DNA that holds instructions for building at least one protein
60
what does it mean when someone says that a gene is being "expressed" in a cell?
the gene is being used to produce a protein within that cell
61
____ is the process of making messenger RNA (mRNA) and requires___.
transcription; RNA polymerase
62
what are mutations?
sudden and unexpected change in the cell
63
how do mutations occur?
can result from errors in DNA replication, can be passed onto next generation in germ cells, enzymes might not catch the mutation
64
How can genetic engineering be used to treat genetic diseases?
gene therapy influences genes to reduce or eliminate effects of a genetic disorder
65
are all mutations harmful?
no, they can be good or bad
66
types of mutations
point mutation, frameshift mutation, rearragned dna mutation
67
what is sickle cell disease?
when a persons red blood cells are shaped differently and do not flow well through blood vessels
68
what is a mutagen?
any chemical or physical agent that can damage DNA by changing the nucleotide sequence
69
what is the viral vector approach?
when an altered virus inserts healthy versions of the gene into the genome of patients