UNIT 3

Question 1

What is the name of the sit at which replication begins?

Answer 1

origin of replication

Question 2

Which molecule seperates the two strands of DNA during replication?

Answer 2

Helicase

Question 3

The primer laid down by primase is made of what molecule?

Answer 3

RNA

Question 4

Which molecule produces the vast majority of DNA during replication?

Answer 4

DNA polymerase III

Question 5

Which molecule removes the RNA primers and replaces them with DNA

Answer 5

DNA polymerase I

Question 6

When DNA Polymerase III has to move in the opposite direction of helicase, it results in what?

Answer 6

discontinuous replication

Question 7

What molecule forms the final covalent bond between nucleotides during replication?

Answer 7

DNA ligase

Question 8

What molecule is synthesized during transcription?

Answer 8

RNA

Question 9

Where does transcription take place in eukaryotic cells?

Answer 9

in the nucleus

Question 10

what enzyme performs transcription?

Answer 10

RNA polymerase

Question 11

what is the name of the sequence of DNA bound by RNA polymerase during initiation?

Answer 11

promoter

Question 12

for eukaryotic cells to initiate transcription, _____ in the initiation complex recruit ___ _____

Answer 12

proteins; RNA polymerase

Question 13

for prokaryotic cells to initiate transcription, ___ ______ is directly attracted to ____ sequences

Answer 13

RNA polymerase, promoter

Question 14

termination of transcription typically requires what structure to form in newly made RNA?

Answer 14

step-loop

Question 15

during RNA splicing, what special regions of RNA are removed from the primary transcript?

Answer 15

introns

Question 16

The point at which the two strands of DNA are separated to allow replication of each strand

Answer 16

replication fork

Question 17

protein that binds to and stabilizes single stranded DNA until it can be used as a template

Answer 17

single strand binding protein

Question 18

a single DNA strand that, during DNA replication, is replicated in the 5′ – 3′ direction

Answer 18

lagging strand

Question 19

short sequences of DNA nucleotides which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication.

Answer 19

okazaki fragments

Question 20

protein that unwinds parental double helix at replication forks

Answer 20

helicase

Question 21

protein that synthesizes an RNA primer at the 5’ end of leading strand and of each okazaki fragment of lagging strand

Answer 21

primase

Question 22

protein that using parental DNA as a template, synthesizes new DNA strand by covatently adding nucleotides to the 3’ end of a pre existing DNA strand or RNA primer

Answer 22

DNA polymerase III

Question 23

protein that removes RNA nucleotides of primer from the 5’ end and replaces them with DNA nucleotides

Answer 23

DNA polymerase I

Question 24

protein that joins 3’ end of DNA that replaces primer to rest of leading strand and joins okazaki fragments of lagging strand

Answer 24

DNA ligase

Question 25

the process by which DNA directs protein synthesis, includes transcription and translation

Answer 25

gene expression

Question 26

the synthesis of RNA under direction of DNA

Answer 26

transcription

Question 27

synthesis of a polypeptide under the direction of mRNA

Answer 27

translation

Question 28

site of translation

Answer 28

ribosomes

Question 29

intital RNA transcript from any gene

Answer 29

primary transcript

Question 30

protein that pries the DNA strands apart and hooks together the RNA nucleotides

Answer 30

RNA polymerase

Question 31

mediates the binding of RNA polymerase and the initiation of transcription

Answer 31

transcription factors

Question 32

the completed assembly of transcription factors and RNA polymerase II bound to a promoter

Answer 32

transcription initiation complex

Question 33

promoter that is crucial in forming the initiation complex in eukaryotes

Answer 33

TATA box

Question 34

removes introns and joins exons, creating an mRNA molecule with a continuous coding sequence

Answer 34

RNA splicing

Question 35

what is the sequence of the start codon in the genetic code

Answer 35

AUG

Question 36

where would you NOT find functional ribosomes

Answer 36

in the nucleus

Question 37

what component of translation is the last to join the initiation structure?

Answer 37

large ribosomal unit

Question 38

in what site to tRNA molecules carrying a single amino acid enter the ribosome?

Answer 38

A site

Question 39

scientists believe that the majority of mutations in humans are caused by...

Answer 39

mistakes during DNA replication

Question 40

how does the mismatch repair mechanism recognize an incorrect base pair?

Answer 40

it recognizes a change in width between DNA strands

Question 41

how does the mismatch repair mechanism distinguish the old and new strands of DNA?

Answer 41

the old strand is methlylated and the new strand is not

Question 42

loosening chromatin structure will result in what?

Answer 42

higher rates of transcription

Question 43

repressor proteins work by binding DNA sequences called what?

Answer 43

operators

Question 44

repression works by blocking which step?

Answer 44

elongation of transcription

Question 45

noncoding regions of RNA

Answer 45

introns

Question 46

change in DNA sequence

Answer 46

Mutation

Question 47

chemical changes in just one base pair of a gene

Answer 47

point mutations

Question 48

replaces one nucleotide and its partner with another pair of nucleotides

Answer 48

base pair substitution

Question 49

mutation that has no effect on the amino acid produced by a codon because of redundancy in the genetic code

Answer 49

silent mutation

Question 50

mutation that still codes for an amino acid, but might be the wrong one

Answer 50

missense mutation

Question 51

mutation that changes an amino acid codon into a stop codon, almost always leading to a nonfunctional protein

Answer 51

nonsense mutation

Question 52

mutation that alters the reading frame

Answer 52

frameshift mutation

Question 53

cancer cells remain localized

Answer 53

benign mass

Question 54

tumor cells invade other tissues

Answer 54

malignant tumor

Question 55

the tumor cells induce secondary tumors at other locations in the body

Answer 55

metastasis

Question 56

acetyl groups are attached to positively charged lysines in histone tails

Answer 56

histone acetylation

Question 57

looks at DNA/protein patterns and how they affect expression

Answer 57

epigenetics

Question 58

blocks elongation of transcription

Answer 58

repression

Question 59

increases rate of initiation

Answer 59

induction

Question 60

entire stretch of DNA that includes the operator, the promoter, and the genes that they control

Answer 60

operon

Question 61

protein that can switch off an operon

Answer 61

repressor

Question 62

repressor is a product of a separate gene called what

Answer 62

regulatory gene

Question 63

molecule that cooperates with a repressor protein to switch an operon off

Answer 63

corepressor

Question 64

small single stranded RNA that can bind to mRNA

Answer 64

micro RNA

Question 65

phenomenon of inhibition of gene expression by RNA molecules

Answer 65

RNA interference

Question 66

RNAi is caused by what

Answer 66

small interfering RNAs (siRNAs)

Question 67

physical expression of a trait

Answer 67

phenotype

Question 68

unit of inheritance that encodes a trait

Answer 68

gene

Question 69

alternative form of a single gene

Answer 69

allele

Question 70

genetic makeup of an individual

Answer 70

genotype

Question 71

both alleles are the same

Answer 71

homozygous

Question 72

alleles are different

Answer 72

heterozygous

Question 73

determines if individual displaying dominant phenotype is homozygous or heterozygous for that trait

Answer 73

testcross

Question 74

two pairs of contrasting traits

Answer 74

dihybrid cross

Question 75

unit factors (traits) assort independently during gameate formation

Answer 75

independent assortment

Question 76

what organism did mendel use in his studies?

Answer 76

pea plants

Question 77

what term is used to express the combination of alleles an individual possesses for a trait?

Answer 77

genotype

Question 78

a single gene trait where heterozygotes have intermediate phenotype is an example of what?

Answer 78

incomplete dominance

Question 79

a single gene trait where heterozygotes exhibit a mixed phenotype reflecting each parent is...

Answer 79

codominance

Question 80

what is the name of a molecule that is recognized by the immune system?

Answer 80

antigen